Open Homes May 2014 - open for bookings!

Here are the links to each home on the booking system (with further details on these and other homes across the East Midlands in the blog posts below).

For last minute bookings (on the day, or the evening before), text or call 07962 453037 with the house name, date and time for the visit you wish to book. We will get back to you with the details and confirm whether there is space still available.

* Book here for Wollaton Road Refurb in Beeston - in mid refurb! (17 May: 2pm)

* Book here for Charnock Avenue Refurb in Nottingham - also in mid-refurb! (18 May: 2pm)

* Book here for Elm Avenue in Beeston - the new addition to our booking system (17 & 18 May:  hourly tours from 2.30pm both days)

If you have any questions or any difficulty booking a visit, just email wbecohouses@gmail.com or phone 07962 453037 and we'll get back to you.

All these homes and others can be found on the Green Open Homes website - just put in your postcode to find a low energy home that is local to you.

Homes which have already opened are listed below. If you missed visiting one of these, there may be opportunities for "ad hoc" visits in the next month or so. Just email wbecohouses@gmail.com with your enquiry as we now have a waiting list for several homes.

* Worwood Drive (left hand branch)  on 10th May between 11am & 3pm and make your way to the house with the gazebo and the green balloons in the front garden.

* Greenstone - a zero carbon barn conversion in East Leake (10 May: 10am and 2pm)

*  Harrow House (towards EnerPHit) - a nearly Passive House refurb (10 & 11 May: 2pm both days)

* The Green Man House - an ultra-low energy new build near Market Bosworth (10 May: 10am and 2pm)

* Peveril House - solar power & ground source heat pump (11 May: 12 noon and 4pm)

Open Homes events across the East Midlands

This May (2014) there will be a huge range of low energy and sustainable homes opening across the UK for interested householders to visit for free. It's a great way to suss out ways to make your home more comfortable and reduce your energy bills.

Many of these events are supported with funding from the Centre for Sustainable Energy, and all the homes are listed on the Green Open Homes website.

Within the East Midlands, there will be our own "Transition West Bridgford" event organising open homes visits in Beeston, West Bridgford, East Leake and Market Bosworth (!). Every home is described in a series of posts below, and also here on the Green Open Homes website.

And we are not the only ones!
There's the "Nottinghamshire and Derbyshire Open Homes Week" here -  (some of our Transition West Bridgford homes are listed here as well, being in the same geographical area).

Then there's the Nottingham Green Door tour here.

And Loughborough Energy Efficient Homes here.

Or if you are north of Nottingham, then maybe Green Homes Sheffield is closer to hand.

Open Homes May 2014 - This year's theme - seeing heat loss!

This year, we have 7 great open homes and a new display.

Details of the 7 homes are in the preceding posts (below). And they are pretty diverse, including two homes that will be "mid-refurb", some extreme refurbs, 2 new builds and a cavity wall insulated house that has cut its energy bills in half with very moderate energy and cost saving measures.

Our theme this year is "seeing heat loss" - because we have been out and about with a thermal imaging camera. We'll have displays up in each home showing good and bad examples of the places where our homes typically lose heat.

For most of the homes open this year it is necessary to book your place - details are in each post below. This keeps numbers manageable and gives you a better chance to see and hear everything!

We send out directions and other useful information (e.g. bus routes, parking etc) to those who book a place, and if for any reason a tour has to be cancelled or rearranged, we can notify you if we have your contact details.

Read on, book on, and I hope you find this year's Open Homes enjoyable and useful!

Open Homes May 2014 - House number 7 of 7

Last but by no means least on this May's open homes list is a 1980's cavity wall insulated house.

It may not sound a likely candidate for a low energy home, and certainly this is not as low energy as the other 6 homes in previous posts. However, when the current owner bought this house, it had an energy rating of F!! Basic improvements (e.g. loft and cavity insulation, draught-proofing and a new gas boiler) along with common sense habits have cut the bills to around half!

There is no need to book to visit this one - just drop by any time between 11am and 3pm on Saturday 10th May and head for the gazebo in the front garden (the left branch of Worwood Drive in Compton Acres, West Bridgford).

Like the other homes open this year, there will be a thermal imaging display to show good and bad examples of the places where draughts and cold spots are typically found in our homes. The home owner (a qualified building surveyor) will be on hand to talk about DIY solutions.

Open Homes May 2014 - House number 6 of 7

Our 6th Open Home this year is on Charnock Avenue near the Queens Medical Centre in Nottingham. Like home number 5 (see previous post), this is an ambitious ultra-low energy refurbishment - and it is mid-refurb!

To book your free place for the 2pm tour on the 18th May 2014, click here.

Here's a summary of progress so far:

An Edwardian bungalow loft conversion and whole-house ultra low energy refurb.  This project is in progress and many interesting features will be still visible.  

Features:

Most U values and thermal bridging to exceed Passivhaus minimum.  Passivhaus style detailing.

160 mm PIR external wall insulation taken below ground to footings.

400 mm EPS floor insulation with slab in the middle and edge insulation down to footings internally.

Loft conversion from below the roof structure and tiles left in place.

Consolar Tubo 12 solar thermal and innovative 500 litre thermal store.

Underfloor heating.

Flexible pipe MVHR by Airflow.

Green Building Store 'Ecocontract 48' external windows and doors set in ply box liners.

High levels of air tightness and ambitious target.

Gas boiler with underfloor heating in the screed.

Pit around the house dug, eaves insulated ready for EWI, which is expected to start in April 2014, ground floor underway.

Open Homes May 2014 - House number 5 of 7

Our 5th Open Home this year (on Wollaton Road in Beeston) is "mid refurb", so it really is a great opportunity to see the nuts and bolts of what's being done now while you can still see the insulation and other elements that will eventually be hidden.

To book your free place for the 2pm tour on the 17th May 2014, click here.

Mid-refurb!
An extraordinary self-build project to significantly extend and energy efficiently refurbish a mid Victorian semi-detached villa.  The owner is carrying out most of the work himself including some fairly serious structural challenges and braving all weather.
Features:
Single storey rear extension shell complete including green roof, Passivhaus style timber frame and oak cladding.
Large side extension substantially underway including a full size basement built next to the existing house which alone took a year owning to needing to underpin sections, build retaining walls and beam others.  Superstructure of extension 3 storeys above basement in Porotherm clay interlocking lattice blocks 365 mm thick (complete) with 100 mm EWI over (planned).
Green Building Store windows throughout, different ranges.  
TJI engineered floor joists.
PV on the workshop.
Solar thermal planned on large dormer roof.
Wood pellet boiler planned.
Double height conservatory planned.

Roof should be complete and windows installed ready for EWI.

Open Homes May 2014 - House number 4 of 7

On Peveril Drive, West Bridgford, just up the hill from house number 3 (see previous post) is another seriously low energy home - achieved in a very different way.

To book your free place for the 12 noon or 4pm tour on the 11th May 2014, click here.

This house was built with extra cavity wall insulation and has subsequently been fitted with solar hot water panels, solar PV panels, a ground source heat pump linked to 2 "sun-boxes" and more recently still a PVT system.

The owner is a technical expert on this system, using it for cutting edge research into the levels of efficiency that can be achieved with a ground source heat pump.

Open Homes May 2014 - House number 3 of 7

Our third open home (Harrow House / Towards EnerPHit) is an ultra-low energy refurbishment which was designed to meet the EnerPHit (Passive House refurbishment) standard.

To book your free visit to this West Bridgford home, click here. Numbers are limited so that you get the best from the visit, with time to put your questions to the home owner during / after the tour.

Although the air tightness figure of 1.08 ACH narrowly missed the target of 1 ACH required for certification, the performance of the house is definitely in line with the EnerPHit standard.

The house provides comfort and excellent air quality in hot and cold weather. Gas use for the last year was a tiny 4800 kWh (heating plus hot water) and electricity bought in from the grid came to 1500 kWh.

In other words, gas costs around £200 per year (plus a standing charge), and electiricity costs almost exactly the same. Altogether, this means that we earn more for the electricity generated by PV panels on the roof than we pay for gas and electricity.

The secret is the Passive House methodology - insulation, air tightness and a whole house ventilation system with heat recovery. The thermal mass prevents overheating in summer and keeps indoor temperatures steady all year round.

Open Homes May 2014 - House number 2 of 7

A little closer to home, in East Leake, is our second open home, Greenstone.

It's a zero carbon barn conversion with a long list of features. And since this home last opened to the public, there have been a few additions to maximise use of the elecctricity generated. If you have not been before, it is well worth a visit!

To book your free place for the 10am or 2pm tour on the 10th May 2014, click here.

·         Super insulated 9” solid brick walls (oldest barn built in 1860)

·         Factory made Insulated roof panels (SIPS)

·         Super insulated floor slab with wet under floor heating (ground and first floor)

·         Extensive use of thermal mass in floors, internal walls and ceiling

·         Itho Whole house ventilation with heat recovery 90% efficiency

·         Triple glazed timber windows with aluminium outer skin (Rationel)

·         Draft lobby with highly insulated doors (Rationel)

·         Air tight construction with measured value of 2.3m3/m2@50Pa pressure

·         Thermal store feed by oversized Solar Hot water panels and heat pump for space heating and domestic hot water

·         10kw roof mounted Solar PV system

·         20kw ground mounted Solar PV system

·         Powerrouter 5kw battery storage system providing solar produced electricity at night and back up electricity in the event of a power cut

·         Two intelligent immersion switches using spare solar generated electricity to heat hot water in 400 and 300L thermal stores

·         Ground sourced heat Pump (GHP) providing space heating and some of the domestic hot water

·         Electric car powered from the solar PV panels

·         Experimental Solar PVT panels providing Earth charging energy from solar panels to improve the efficiency of the GSHP

·         Recently installed Web based energy monitoring equipment measuring electrical use, solar power generated, appliance consumption, heat generation

·         Rain water recycling from underground tank to provide water for toilet flushing and garden irrigation

·         Presence and daylight sensor light control in common areas of the house

·         100% low energy lighting and low energy appliances

·         Reserve wood pellet 5kw stove in case of power failure

Interesting facts/results:

·         It works!

·         It has met its target energy consumption with 3 years’ worth of all power consumption (electricity) 10,500kwh/year

·         The house is now a net exporter of  Solar generated electricity providing a very useful additional income stream

·         It  also provides free electricity to charge 2 or more electric cars the first of which is doing really well (Volt)

·         The family loves it because it is comfortable and pleasant to live in all year round

Open Homes May 2014 - House number 1 of 7

Of the homes we're opening to the public in May 2014, this is the first to be featured here in the run up to the open days.

The Green Man House is a new build to almost Passive House standard, and it's near Market Bosworth! It may seem a little way outside Nottingham, but it's a great house so it would be a shame to miss it out.

Owner Peter said

"Of the number of approaches to building a ‘green house,’ we decided to emulate the Passivhaus standard. We decided on a timber frame construction built off site, with good insulation, air tightness, solar water heating, and a ventilation system with heat recovery. The house was orientated and designed to take advantage of the warmth of the sun within a fairly tight site.

The house has performed well since it was completed five years ago, although it just failed the Passivhaus air tightness standard. A log burning stove is used on colder winter evenings to bring temperatures up to a comfortable level and to boost the hot water supply."

If you would like to visit this house, click here to book your place. Numbers are limited so that you get the best from the visit, with a chance to put your questions to the home owner.

Open Eco Homes event in May 2014

If you are interested in seeing inspiring examples of energy efficient homes, there are various events coming up across the UK in May.

Here in the East Midlands, we're joining in the fun as usual. There are plenty to choose from in Nottinghamsire and Derbyshire (here) and in Loughborough. 

Transition West Bridgford's Eco House Group has a number of interesting homes lined up and a few more to be confirmed. If you would like to receive an email invite once all our homes and opening dates and times are confirmed, just email wbecohouses@gmail.com to join the mailing list. Or check this website as every home will be featured here over the next 4 weeks and booking details will be provided.

If only we could see the heat escaping from our homes....

Well, you can of course see heat escaping from a house using a thermal imaging camera. Taking photos inside the house shows the cold spots where the cold gets in (i.e. heat is lost). From the outside, you see hot spots where escaping heat emerges.

In December 2013, Transition West Bridgford put in a bid for funding to buy a thermal imaging camera and now we are ready to use it!!

If you live in or around West Bridgford and think you might be interested in a thermal imaging survey of your home, get your name on the waiting list here. There's no obligation - this is just so we can contact those who are likely to be interested in a home survey or a community event showing the typical areas of heat loss.

We hope to carry out the visits in March (before the weather gets too warm).

For the full details, here's the press release:

E.ON’s Energy Action Fund powers Transition West Bridgford’s energy education

Community group, Transition West Bridgford, has been awarded a grant of £1,790 from energy company E.ON to promote energy efficiency across the local area.

The grant from E.ON will enable the organisation to purchase a thermal imaging camera, which will be used in free educational events for local residents. These workshops will help residents to understand how energy is commonly lost in the home and subsequently how this can be reduced, potentially resulting in lower energy bills.

Images from the camera will also be used in educational materials and online to raise as much awareness as possible across West Bridgford with the wider community.

  

The E.ON Energy Action Fund is part of the company’s commitment to helping local communities use no more energy than they need, benefitting both individual groups and the wider community.

 

Jake Jackson, Treasurer at Transition West Bridgford, said: “The funding received from E.ON will have a positive impact on the local community. The camera will not only be used to support educational events and materials, but also to carry out paid thermal imaging surveys for individuals and businesses.

“The funding raised through these surveys will provide long term support to Transition West Bridgford, enabling us to continue running the awareness raising events.”

Amy Cross, Senior Community Relations Executive at E.ON, said: “We’re really keen to support this project as it has the potential to educate many people across the community and the initial funding will help this to continue. We hope this will make a big difference to local people.”

For further information about Transition West Bridgford’s forthcoming Energy Saving Event or to find out more about the thermal imaging surveys, email wbecohouses@gmail.co.uk or visit http://transitionwb.blogspot.co.uk/. To find out more about how E.ON can help you save energy visit eonenergy.com/savingenergy.

Event - Know your energy efficiency options, grants and loans!

When and where: 28^th November from 7-9pm in West Bridgford, Nottingham.

Whether you are just thinking about a few low cost options for saving energy or wanting to find out about current loans and grants for energy efficiency work, this is the event for you.

For example, would you be interested in Solid Wall Insulation if there was a government scheme to reduce the cost?

If your home is not suitable for Cavity Wall Insulation, there is a new scheme to subsidise the cost of External Wall Insulation (EWI) and Internal Wall Insulation (IWI), which extends to a range of other energy saving improvements made at the same time. This subsidy, called ECO, can reduce the cost of the work by several thousand pounds and is not income-dependent – so it is worth knowing more about it!

There will be 10 minute talks on:

• ·        Insulating solid wall homes – what is the ECO subsidy? Could it help me?
• ·        Is the Green Deal a great deal? Or are there better alternatives?
• ·        Energy Efficiency and a Healthy House – how to do both.
• ·        Draught-busting and other low cost / DIY ways to save energy.

Then from 8-9pm there will be mini-surgeries, giving you the chance to put your questions to the speakers in small groups or individually.

If you would like to know more, why not come along to this information evening at Jesse Gray Primary School in West Bridgford, Nottingham on 28^th November from 7-9pm?

For more information, email wbecohouses@gmail.com. To reserve your free place and get full details, go to Event Brite at http://www.eventbrite.co.uk/event/9210154821/eac2. Numbers are limited so please book in advance.

Open Homes in September

Two homes in Nottinghamshire will open their doors this month to people who are interested in low energy new build and refurbishment.

On Saturday 28th September at 2pm, there are still spaces available to visit an ultra low energy home near Newark. See the previous post for more about the house and email wbecohouses.co.uk if you would like the chance to join the tour.

On Sunday 29th September, an ultra low energy refurbishment in West Bridgford will open to visitors. All spaces have now been taken for September so a second date will be arranged. Just email wbecohouses.co.uk to join the waiting list if you are interested.

Another ultra low energy new build here in Nottinghamshire

How is it that here in the UK our new build standards match what the Germans were doing about 30 years ago in terms of energy efficiency? Surely the government could set the bar a bit higher? It is by no means impossible - individuals are quietly getting on with it and showing what can or should be done....

It's great to hear the experiences of others as they build or refurbish their homes, and make them energy efficient in the process. I met Roger in 2011. At that point he was planning the construction of his own home - with the Passive House standard as the target.

And now it is done, he's spent his first year in the house, and he has very kindly agreed to open his home and share his experiences with a limited number of visitors interested in low energy new build. (Just email wbecohouses@gmail.com if you would like to know more about that.)

Here are the vital statistics of the new house, in a village which is off-gas:

Built to Passive house standards using traditional materials

High Thermal mass (to maintain a more stable temperature, to soak up excess heat in summer)

`A` rated EPC

8.1 kw solar PV built into roof structure

No gas boiler , no ground scource heating  

Just a 3 kw immersion heater sufficient to keep the house at 21 degC through last winter.

PV also powers an electric car.

Rain water recovery.

Contemporary design detailing in a conservation village setting.

Some innovative construction details such as no strip foundations, house built on raft of insulation.

Precast concrete 1^st floor.

SIPS panel roof.

Open Homes events in September 2013

During September, there will be Open Homes events running in many parts of the UK, many of them belonging to the Superhomes network.

Here in the Nottingham area, we'll be joining in the fun with Superhomes and other local low energy homes opening their doors to the general public.

Whether you are mulling over the most cost-effective ways to save energy next winter, or considering more costly ways to save energy and improve comfort in your home, keep an eye on this blog or email wbecohouses@gmail.com to make sure you get all the details. It's also a chance to find out more about the Green Deal and government incentives to help with the cost of external wall insulation, other energy saving measures and renewables.

If you already live in a low energy home and would like to open your home as part of this event, do get in touch - it's always great to have a wider range of examples.

Low energy home in Derby offers tutorials

If you are interested in learning about a local low energy home (in Derby), this could be the perfect opportunity.

Homeowner, Kate, is offering some free tutorials about her experience of transforming her home from a very ordinary brick house into a "passive house" that needs almost no heating.

Click here for more details and to book:

http://thornhillecohouse.eventbrite.co.uk/

An intro to the Green Deal Loan and the ECO grants

Like me, you have probably been cold called recently by companies offering you "free" stuff under the Green Deal.

Being quite well up on the ins and outs of the Green Deal, I do like to ask a few questions for my own entertainment and suss out whether the company concerned is prepared to be honest and give good info about the Green Deal, or whether they are being deliberately misleading.

Here's a very basic summary that includes some useful info about the Green Deal and the ECO. The key point to note - the Green Deal is a loan (and not a particularly cheap one), and the ECO is a grant.

Or if you have a warped sense of humour and would like an alternative overview (but perhaps not quite as useful), here's a little parody on uTube. (Warning - contains some strong language and may cause offence.)

Carbon Dioxide levels reach 400ppm for the first time in ~4 million years

This week, we've reached 400ppm of CO2 in the atmosphere for the first time in about 4 million years. In other words, efforts so far to reduce carbon emissions are not enough. Much more needs to be done just to stop emissions rising. What is really needed is to get back to safe levels (350ppm would be a good start).

So what did the world look like the last time there was 400ppm of CO2 in the atmosphere? Click here.

And here's a short and to-the-point slideshow which illustrates where we are at.

Are we destined over the next generation or two to see 40m sea-level rise, a large increase in pests and diseases as temperature zones shift, challenging weather conditions, impacts on our economies and food supplies? To some extent, we are seeing these things now. But a massive and widespread effort to reduce emissions would minimise the chances of seeing such dramatic changes in the future.

Ironically, we have the capacity to make huge changes straight away with hi-tech and low-tech solutions (including options as humble as changing behaviours). What is urgently required politically, in communities and individually is the will. So simple and yet so difficult.

Old gas boiler? Big bills?

If you live in West Bridgford, have an old gas boiler, and maybe a large or solid wall house that is expensive to heat or just doesn't get that warm, read on....

(click on the image to see at full size) Call 07962 453037 for further details.

Lots going on in March

Transition West Bridgford's Eco House team have had a busy winter helping people towards saving energy...

We organised a dozen thermal imaging surveys carried out by David Hill of Carbon Legacy - which were very illuminating judging by the comments from householders who now see their homes in a new light! Seeing where the cold comes in and the heat goes out can be quite informative!

Volunteers in the group have been helping to write and circulate information about a local offer of free Green Deal Assessments to householders who may have high gas bills if they live in a large or hard-to-insulate house with an inefficient gas boiler (see details on an earlier post).
     
Some of the team will be helping out on the Energy Bus in West Bridgford's Central Avenue on Saturday morning (9th March) from 9.30am until 2.30pm. Come along and have a chat, particularly if you or someone you know would like a free assessment - available only in March so you'll need to be quick!

Three homes in West Bridgford held an open homes day on 3rd March as part of Nottinghamshire and Derbyshire Ecohomes Open Week, attracting about 50 visitors in total.

And if you missed out on those visits, the Nottinghamshire and Derbyshire Ecohomes Open Week is not yet over - click here for other open houses.

Later in 16-24 March, it is National SuperHomes open week, when some of Nottinghamshire's Superhomes will open their doors again - click here to find a SuperHome open day near you.

Peveril Solar on Ecohomes open day

There is a programme of visits to Ecohouses in the region, from 3rd-10th March.
Peveril Solar is one of the houses on the list and we are open on Sunday 3rd March at 2pm and 330pm. You need to book ahead by emailing info@wbecohouses.co.uk or DNC at dnicholsoncole@gmail.com .

This is the leaflet by Everybody's Talking, who have arranged the event. It includes a succinct explanation of the technology. Peveril Solar is the first house in the UK to be entirely solar heated all year round.	Although the official time is 3rd March, you might be reading this after that date, but please be assured, that visitors with a serious interest in Solar Earth Charging are welcome at any reasonable date, by first emailing the DNC address above.

Energy saving schemes and events

Looking into ways of making your home more energy efficient and cheaper to run?

If you live in West Bridgford and your home is heated by an old gas boiler, see the post below for details of a scheme which may interest you.

If you are looking for inspiration or information about a range of energy saving options, why not go along to an open house event and see what other home-owners have done? Details on our local open home day (3rd March and additional dates now added) are given in the second post below, together with links to regional and national open homes events in the same month.

Open Homes, March 2013

As part of regional and national open homes events in March, 3 houses in West Bridgford will open their doors to visitors. If you want to take part, click here to register your interest, see which homes are open and when, and to request a booking.

The oldest, built in the 1890's, was a G rated house before it was turned into the "Nottingham Eco Home". Full details can be seen here.

The next, a typical 1950's house of solid wall construction, has been extensively refurbished and now approaches the new Passivhaus Refurbishment (EnerPHit) standard. Further details can be seen here and here.

The youngest house on the list was built in 2006, and the owner was able to dictate above average levels of insulation as it was built. This house uses solar energy to match its entire annual heating and hot water requirements. For more details, click here.

If you live in or near to Nottinghamshire and Derbyshire, a diverse range of events running in early March will be listed here:
http://www.everybodys-talking.org/ecohomes/events

And later in March, it is national Superhomes Week, when homes all over the UK will open their doors. Look for events running near you on http://www.superhomes.org.uk/.

Thermal imaging

This time last year, a few lucky householders (those who put their homes forward as case studies in the HOBBS report) had thermal images taken of their homes.

Within the Eco House Group, many have expressed an interest in having this done and I promised that I would look into it. I've just had a trial run on my own home (see the blog for the full details), and I'll be emailing out to the Eco House Group when I have dates and details for those who would like their homes to be assessed in the same way (for a very reasonable fee to cover the cost).

If you are in or near West Bridgford and would like to join the Eco House Group email list, just email wbecohouses@gmail.com and ask to be included.

Arguments for and against PVT

9 Jan 2013: DNC writes: There's an interesting article on the Solar Blogger website by Stuart Elmes. It's about PVT (Photo-Voltaic-Thermal) panels, and he has a more technical PDF linked to it.

PVT panels are, in essence, a PV panel with a mesh of liquid cooling tubes behind the PV surface. For higher PV capture, the panel is uncovered, but for a higher thermal capture, the panel has a glass cover over it and insulation behind.

   I am a great believer in PVT, but the only properly productive application for it that I can see is when it is associated with low-grade thermal storage and heat pump.
   It could also good for those who have a limited area of roof, and haven't enough space. If you have enough roof surface to play with, the best place for PV might not be the best place for thermal. Ideally, a house needs 28-30 square metres of PV to attain the 4 kW that is recommended for the Feed-in-Tariff in the UK - a smooth, unobstructed and unshaded area facing south is the best. PV arrays normally have an air space under them and they work best on sunny days with a cooling northerly breeze that can get under the panels.
   For solar thermal, the size can vary from 1sqm to 4sqm. Above that, it gets a bit silly unless you are addicted to hot showers all summer. So Solar thermal can often work well in smaller locations on hipped roofs, or large dormers, providing you can get a south aspect. Another criterion for best place might be closer to the optimum positions of a tank and the plumbing.
   The idea of PVT is that you get a larger area for thermal, and the PV element is cooled by the liquid passing under it.

   The paradox is this: for you to get useful heat to a water tank, you want the panel to run very hot, but for the PV panel to run well you want it to run very cool. Stuart's article explains the paradox well.


   So for a solar thermal water tank you want the circuit to run at 50-70ºC, and when the tank reached 60ºC, the circulation would stop. If you ran PV at these temperatures it would be unworkable. If you want PV to be optimised, the purpose of the liquid has to be to cool the PV, so it should be circulating at 15-20ºC. A normally air cooled PV panel reaches 40-50ºC surface temperatures on a hot summer's day, but the PV cells run better is the wind is blowing.
   If the water tank reaches optimum temperature and turns off the pump, the sun will make the PV even hotter, and as there would be insulation behind the PVT panel, there's nothing to stop the liquid temperature getting dangerously high. Stuart's article refers to the risk of temperatures as high as 220ºC. (I am informed by Newform that this might be a mistake, as Powervolt panels permitted to stagnate seriously haven't gone higher than 100ºC, although the glass topped Powertherms might get hotter.)

Therefore, for thermal storage for a heat pump, the panels running at 15-20ºC would be warming an infinitely large tank size, the earth, whose base temperature would be 10-12ºC, so there will always be a benefit. There is no risk of any of the system reaching stasis and turning off because earth has a vast thermal capacity in relation to the size of the panel array or the size of the building above it.

    Having a larger surface area than normal solar thermal panels (28sqm instead of just 2 or 4sqm) the solar thermal gain for the store - large volume of low grade thermal energy is going to be very good! One thing that my experiment has shown is that the ground does not get 'hotter', but the volume of earth that is warmed up to a moderately warm temperature gets larger.

    One thing about any of these systems, is that they must keep running. If the system circulates reliably everything is the right temperature. If a future owner of this house just turned the solar circulation off in summer, there would be problems if temperatures rise and there isn't sufficient capacity for expansion of the liquid.

It's windy out there!

A piece of news that I heard via the AECB (Sustainable Builders Association) and CAT (Centre for Alternative Technology):

In the early hours of this morning (22nd November 2012), electricity production from wind power actually exceeded electricity from gas! Between 3:30am and 5:30am, UK wind turbines produced around 4.2GW whereas gas power stations contributed a bit less than 4GW.

By the way - if you are thinking of checking your draught-proofing around the house, then a windy day is a great time to do it. Hold your hand near to doors frames, window frames, skirting boards, chimneys and so on to work out where cold air is leaking in and warm air is leaking out.

If you have any specific questions about draught-proofing, just email wbecohouses.co.uk and the answer might get posted on this blog.

Energy Event in November

With winter on its way and energy bills rising, you may be considering what else could be done to improve comfort or reduce the bills in your home. If you are in easy reach of Nottingham, why not come along to our next energy event...?

(just click the flyer below to zoom in)

Nottingham ecohouses visit

10 October 2012: The West Bridgford Ecohouse group were invited to take a tour of the Creative Energy Homes on the campus of the University of Nottingham. There's a group of five of them, demonstrating different technologies. Some are lived in by postgrad students or staff.

Tina asks a question about the BASF house. Many thanks to the kind PhD student who showed us round the buildings.	The house has a large south facing winter garden, with solar shading to prevent over heating. The ground floor is built with concrete filled foam blocks and the upper floor walls and roof are SIPS panels, structural insulated panels.

MVHR - a householder's experience

Following a request for more information on Michael and Mo's low energy refurbishment - specifically about their part-house MVHR system - Michael has very kindly written a summary to share.

Just in case you are wondering, MVHR systems usually come in 2 forms. One is the whole house system which draws air from all the kitchens and bathrooms, and puts fresh, warmed air into bedrooms and reception rooms. The other option is to use "hole in the wall" fans with MVHR combined, just in bathrooms and kitchens.

Michael's system, on the other hand, sits between the two. As the air tightness of Michael's house has been improved well beyond the norm for a house of that age, the MVHR system may save some energy from the heating bill by retaining the heat from the outgoing air.

The most efficient of these systems can cost less than £30 per year in electricity to run (even if on 24/7) and can take less energy to run than the heating energy that they save.

Here's Michael's review of his MVHR system to date.

"TITON - HRV-1.75 Q+ unit"

Having installed this newly introduced unit 12 months ago, I am extremely impressed by the performance achieved to date.

The system extracts warm damp air from three areas, bathroom, en-suite shower and kitchen.  It operates on a "trickle" - 24/7 basis with switchable boost in the bath & shower areas.

In the "trickle" mode, it is inaudible but obviously in action when on boost.  The outlet vent in the dining room produces some noise & movement of air. This fresh air is pre-warmed by the outgoing stale damp air which is then vented through the roof, above the unit installed in the loft void. All loft trunking is contained in insulation jacketing to maintain efficiency.  As the house has a good air-tightness, over & above current building regulations, this, too, aids to the total efficiency of the system.

In summary, this efficient unit has produced a stable internal environment within our home. 

At present, no continuous monitoring of humidity levels has been instigated but it would be an interesting exercise to carry out. 

Perhaps one for the future!

Open house visits this weekend

15th September
• David Hill's zero carbon barn conversion in East Leake (superinsulated, renewable technologies and now an electric car)
There will be a tour starting at 2pm.

16th September (10 mins walk between this house and the 2000's house)
• 1950's ultra-low energy refurbishment (passivhaus) in West Bridgford
• Website (http://www.eco-retrofit.blogspot.co.uk/)
There will be a tour starting at 2pm and a later one from 3.30pm.

• 2000's house with cutting edge renewable technologies in West Bridgford, and a ultra-insulated extension under construction
• Website  (http://chargingtheearth.blogspot.com)
There will be a tour starting at 3.30pm.

Contact wbecohouses@gmail.com 

to book your place and to obtain location details.

Open house visits: more about the Peveril solar

Tina asked me to write a bit about one of the two houses that are on the visit of 16th September at 2pm or 3.30 pm. There is only a ten minute walk between the houses, so we have arranged is so that you can see one and then walk to the other.
http://wbecohouses.blogspot.co.uk/2012/08/open-house-visits-in-september.html

The Peveril Solar house is Net-Zero due to an interesting combination of solar technologies - Photovoltaic, Surya Sunbox, Kingspan vacuum tubes, underfloor heating and a Ground source heat pump. During the visit, the way in which these interact will be explained. There are other energy saving things to see, such an an induction hob, light tube, voltage regulator, partial heat reclaim.
Net-zero means that its entire heating and hot water requirements are met by PV power generation, annually. Yes, is entirely solar heated the whole year round using electrical and thermal storage.

Another interesting thing is that a new house extension is being built, being a unique form of construction. The architect is adapting structural insulated timber panel construction but applying hand built methods that avoid thermal bridging, making it ultra insulated, but keeping the walls to half the thickness of a brick-block wall. The extension will include one of the first domestic installations in the UK of PV-Thermal combi panels, the PV providing off grid electricity and the thermal being used to charge the borehole 16 storeys deep under the house.

What to do this weekend?

Just in case you are wondering what to do this weekend (or the next few!)....

There is plenty going on. Over on Transition West Bridgford's blog, there is information about the Small is.... Festival. (Never heard of it - have a look!)

If reducing energy use in the home is on your mind as autumn approaches, or you are just curious about low energy homes, then scroll down this blog for open house events in September.

Aiming for EnerPHit

In line with Superhomes week in September, we've decided to put some local case studies of low energy homes on the blog, some of which will open their doors to interested visitors (see previous posts)

Kate and Geoff's house in Derby is likely to become a Superhome very soon. This house is currently being refurbished to EnerPHit (the Passivhaus refurbishment standard).

This 1950s detached house is East-West facing and has been extended at some point to give 5 bedrooms, and a 1980s single storey extension. 

The refurbishment work includes insulation under floors, a "warm roof", external wall insulation (and some cavity wall insulation - rather odd original construction to say the least).

The work also includes Passivhaus-suitable triple glazing, a new boiler but some old radiators retained, lots

of water saving improvements, a recycled solar PV system, a tank suitable for adding solar hot water in the future, ...plus big fruit and vegetable plots, and ex-battery chickens!

Open house visits in September

Several local homes which have been built or refurbished to use less energy will be opening their doors during September to interested visitors. Visit and ask any questions you like.

Keep an eye on the website as additional houses and other details may be added in the next few days:

1st September
• 1950's ultra-low energy refurbishment (passivhaus) in Derby.
There will be a tour from 10.30am to noon and a later one from 1pm if numbers require a second tour.
(Child-friendly arrangements are possible here - just ask for details).

8th September
• Penney and Gil's 1890's house (now very low energy indeed) in West Bridgford
There will be a tour from 11.30am and 1.30pm,

• Edwardian home in Carlton - book your visit on 8th or 9th September via the Superhomes website: (http://www.superhomes.org.uk/superhomes/nottingham-carlton-mayfield-road/)

15th September
• David Hill's zero carbon barn conversion in East Leake (superinsulated, renewable technologies and now an electric car)
There will be a tour from 2pm,

16th September (10 mins walk between these two)
• 1950's ultra-low energy refurbishment (passivhaus) in West Bridgford
• Website (http://www.eco-retrofit.blogspot.co.uk/)
There will be a tour from 2pm and a later one from 3.30pm,

• 2000's house with cutting edge renewable technologies in West Bridgford, and a ultra-insulated extension under construction
• Website  (http://chargingtheearth.blogspot.com)
There will be a tour from 2pm and a later one from 3.30pm.

Unless indicated otherwise, contact wbecohouses@gmail.com 

for more details or to book your place.