Treehugger.com had an article on this prototype system that combines hydroponics and a fish farm into one unit for all year round veggies and a few fish.
The prototype Globe/Hedron “is a bamboo greenhouse designed to organically grow fish and vegetables on top of generic flat roofs. The design is optimized for aquaponic farming techniques: the fish’s water nourishes the plants and plants clean the water for the fish,” according to designer Antonio.
At yesterdays Green Building Event at the Eden Project the news came through (Tweet feeds) that Greg Barker, the UK government energy and climate change secretary tweeted:
“Having listened carefully to industry, we are looking at scope for pushing back a little the next proposed reduction in the solar tariffs.”
They were due to be cut in July from the current 21p per Kw.
If you have / get solar panels there are several return on investment streams:
One of the Eden Project show talks had these figures, that may be high end in terms of them being from a chap that is from a PV installation company.
The Energy Saving Trust has figures of:
A typical domestic solar electricity system with an installation size of 3kWp could earn:
Scaling this up to a 4kWp system that’d be £893.
Being fair to Tony at Cornwall Solar Panels (Tel 01872 562 775) who gave the above figures, his entire talk was centred around there being no such thing as the best solar panel, but the best solar panel configuration for a particular situation. Panel efficiency, shape, size, drop off with heat, drop off with shading, the roof angle and a bunch of other variables (string or per panel inverters) all influence the efficiency and the system cost and so the Return On Investment (ROI). His talk went over about a dozen different installations they’ve done and have figures from. The clear implication / impression is that they are doing installations all over Cornwall.
The Energy Saving Trust did a survery on a large number of UK and Republic of Ireland solar hot water systems.
Distribution of the surveyed / trial locations:
So for Silver Spray in Cornwall, should get better results as more sunshine:
The solar energy input to the hot water cylinder is at a maximum in summer, with back-up heating providing more energy in the winter months.
It’s key to set the backup (non solar) heating system to run so that the solar heating can be most effective and the house occupants have hot water when desired.
How to improve the performance of a solar water heating system:
- Using boiler timers and/or solar controllers to ensure that water is only heated by the back-up heating sources after the water has been heated to the maximum extent possible by the sun.
- Timing of back-up heating and hot water use. Systems
provided more energy when the back-up heating was
used just before the main hot water use or at the end of
the day. This provides a better opportunity for the solar
collector to heat the water rather than using the back-up.- Having an adequately sized dedicated solar volume (that is, a portion that can only be heated by the solar water heating system). Where a dedicated solar volume is not used (for example in systems that do not require the existing cylinder to be changed), the timing of back-up heating has a particularly important impact on performance.
- Insulation is a vital part of this, as systems with poorly insulated storage cylinders can suffer from inadequate hot water provision in the mornings.
These black panels were on display:
http://www.thermogroupuk.com/thermodynamic.html
These black aluminium panels have refrigerant fluid pumped into them. The heat absorbtion of the black panels changes this to a gas, that is sent to a compressor, which releases heat energy in the heat exchanger where the heat goes into the water. The gas then goes through an expansion valve, putting it back to a liquid before it goes back to the panel. (See explanation & figures below forum comments below).
http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=7740&page=1#Item_0
Also from the forum, from their N. Ireland distributor:
The system is not new technology; it is basically a freezer “in reverse” and like a freezer consists of a heat collecting panel(s), refrigerant piping and an integrated electric heat pump. It is a clever application of well tried and tested technology that has been around for almost 100 years. The panels are made from weather protected anodized aluminium and are not vulnerable to extremes in hot or cold. They are light, weighing only 8 Kg and may be mounted in virtually any orientation or angle. It has been estimated that 25% of the energy absorbed by a panel comes from solar irradiation, the balance taken from air and rain. Both sides of the panel are available to collect energy. The company that manufactures the system is based in Portugal and to meet growing global demand they have just built a second factory reflecting their 25 year history of success with the product.
You can check them out at http://www.energie.pt/?cult=uk
The Energie system is fully scalable from 1 – 2 panels for domestic hot water, to 4 – 24 panels for central heating right up to 40 panels for large volume hot water requirements. Note that additional panels simply mean faster water heating times, not higher water temperature which is set to between 55 and 60 C maximum. A typical domestic installation for domestic hot water will have a 250L cylinder with a single panel mounted on the roof.
The heat pump is integrated directly into the Energie cylinder so an existing hot water cylinder cannot be used in this configuration. For central heating and large volume hot water requirements the heat pump (Solar Block in Energie speak) is a stand-alone device. Energie cylinders are either stainless steel or enamelled steel and can come with an additional coil for connecting into a backup heat source if desired. Sizes range from 200L to 6,000L.
All Energie Thermodynamic Systems are accredited under the MCS scheme.
The system uses 407A refrigerant and doesn’t need topping up. The only maintenance may be the occasional replacement of the sacrificial anode in the cylinder should you live in an area with soft water.
Another point raised concerned the panel frosting over in winter. This is possibly best addressed by personal experience. I installed a 300L single panel system in my home at the start of this year, and although there was some frosting in the very cold weather at that time on the top surface of the panel, the bottom side was clear, and we always had enough hot water. Eight months later we have never had call to revert to either our central heating boiler which has been turned off these past 5 months, or the small integrated immersion that comes with the Energie cylinder. I estimate from measurements I have taken that the Energie system has used an average of 3.6 KWh of electricity per day over the 8 months January to August for our 4-person household at a COP of just over 3.
Hundreds of Energie systems have been installed successfully throughout Ireland over the last 4 years and having come through last winter are well tested for the vagaries of the UK and Irish climate.
Finally some additional information as supplied by Energie can be found using the link below. http://www.e3renewables.com/downloads/
From:
www.thermogroupuk.com/thermogroup_pdfs/Thermodynamic%20Technical%20Information.pdf
1. Aluminium Panels
Refrigerant fluid circulates through the panels and absorbs heat energy from the atmosphere. This increase in temperature changes the fluid into a gas.
2. Compressor
The gas then passes through a compressor and the temperature increases.
3. Hot Water Cylinder
The hot gas then flows through a heat exchanger in the Thermodynamic Block which transfers the heat into the water, which can be used for sanitary hot water, space heating or larger applications such as swimming pools.
4. Expansion Valve
The gas then passes through an expansion valve, reverts back to a liquid and flows back to the panels to
repeat the process.
I read or heard at the show, that increasing the number of panels increases the speed at which the system works. So I think you could add a panel to make the system work faster at grabbing the optimum conditions? (Need to ask them)
| Air source heat pumps | Thermodynamic |
|---|---|
| • COP of around 4 • Outputs of 6-18kW • Outdoor noise pollution • Requires regular maintenance • Efficient to just below 0 degrees C • Fixed sizes • Fan assisted, low active surface area |
• COP of up to 7 • Outputs of 1.7 – 53 kW • Silent outside • Only one moving part • Works down to -15 degrees C • Total flexibility • Active surface area of 3.2m2 per panel |
| Standard Solar Thermal Panel | Thermodynamic |
|---|---|
| • Provides up to 70% of your hot water • Must be mounted south facing for best results • Needs backup from a boiler or immersion heater • Needs sunlight – low performance in winter/night • Can only assist central heating • Fragile glass panels |
• Provides up 100% of your hot water. • Can be mounted south/west/east/north on a wall • No backup required – Not connected to boiler • Works in the dark and down to -15OC – 24/7 • Can provide 100% of your central heating • Aluminium – tough, long lasting, anti corrosive |
From www.thermogroupuk.com/thermogroup_pdfs/Thermodynamic%20Case%20Studies.pdf:
So how much would a central heating and hot water system cost per annum ?
– those figures have an assumed electricity tariff of £0.14/kWh. If the system is part driven by my own solar panels, the cost would be reduced (although you need to factor in the capital cost of the solar panels.)
Need to add in the cost of having it all installed and signed off to the level that’ll hopefully get the Renewable Heat Incentive.
From www.thermogroupuk.com/thermogroup_pdfs/Thermodynamic%20Kit%20Retail%20Prices.pdf
Thermodynamic kits ship pre-gassed, ready for installation and include the following:
The above thermodynamic kits are suitable for supply of sanitary hot water in domestic applications. Thermodynamic systems for Ambient heating or larger applications require a more detailed specification to ensure we provide you with the right solution.
I’ve emailed them for a rough quote.
There may be a problem with the current Silver Spray plans and the angles for the solar panels. The current plan is for the panels to be bolted onto the proposed flat roof at the back.
I ran figures through the Energy Saving Trust calculator for a few variations at the Silver Spray postcode location:
At the Ecobuild expo, there were a LOT of companies who had photovoltaic elec or water heating systems. Few were combined PVT (both electricity and heating water). So I started asking why. Speaking to those that make the panesl and installers / advisors the consistent reply was that the reduction in output of both systems was more than 50% down on what you’d get if each was stand alone. One company that produced PV and PT panels said that:
Yes, it’s still good to cool down PV panels, with ventilation, or even surrounding green roofing. But it seems that cooling them, by linking in pipes to generate hot water doesn’t work. It seems that the temp hot water panels work at is so high to be efficient, that takes out too much electricity production. Or you compromise the amount of hot water production by having the panels at a much lower temp. ie to be efficient they both operate at vastly different temperatures.
So that means looking at seperate systems for electricity production (PV), hot water productin (PT) and something for when the sun isn’t shining for hot water (for taps and heating).
Today, Robert from ra-studio, took to visit a house in Portloe that he worked on before he set up his own practice.
Rob, post visit dropped this in an email to me:
I hope you found the trip over to Claire’s place useful yesterday – it’s sometimes good to experience spaces in a more physical sense / situation, and perhaps helps you to visualise how some of your spaces could feel. I think there are obvious parallels between Sea House and Silver Spray (connection / views / relationship with the sea), and seeing how it has been handled there, I hope was helpful for you.
Yes, well worth the visit. It was fantastic to meet such an obviously happy client (and her cool, crazy young dog, Zola).
Their project was serialised in the Telegraph:
So many things about the house, that I hope to include in Silver Spray. The feeling of space, the flow through the house, the views, the natural materials ……
The house looks over the village and was designed to fit into the slope. Without the red circle, it’d be a chunk less obvious !
You drive up the drive and see the studio on your left with the house a bit beyond.
The cladding on the studio is the same as on the house, but it hasn’t yet worn to the same more grey colour / tint.
The house has an amazing central “spine” so that as you walk up to the front door, you see through to the view.
Although the stone detail of the wall below the cladding looks stunning on this house, it’s not something I feel will work for Silver Spray. Except !!!!! maybe for the rear wall of the courtyard. Well something needs to go on that wall. Perhaps it’ll be a retaining wall held back by Gabions (steel cages of rocks). But a quick on-line search suggests the life of Gabions, which is down to the life of the steel holding them together is 50 to 60 years. I suspect less in Silver Spray site, so close to the sea. Damn, as they’d be great.
The slate flooring runs from around much of the house, straight into the house, where it’s apparently super easy to clean. The texture it gives was fantastic. The same slate was used for the external window sills.
Almost all of the windows are by Velfac, with thin profiles, nice colours etc.
This upstairs window has a piece of glass over the front to create a “Juliet Balcony”. Which will work great for the second bedroom.
I’m still not a fan of the idea of wooden decking. Here there was a mixture of slate and wooden decking.
Coat room to the left as you walk in 🙂
Lovely doors, floor and wooden stairs:
Nice detailing on this sliding door that can close over the entrance to the kitchen.
Wide, light floor boards. Interestingly, wooden floors upstairs. I was thinking carpet, but this did work well. OK they have light coloured tiles in the bathrooms upstairs. The bedrooms had good integrated storage.
The above white TV makes it less dominant on the room. Also a superb idea that it pushes against the wall, but is on an arm that can come out and so be viewed from the seating etc. This could be a great idea for in any bedrooms. Although I’m not planning TVs in the bedrooms, it’d be good to allow this future option.
Having a TV in the 2nd bedroom for guests could be a nice touch.
Pebbles in a gulley outside the door, to prevent splash up from rain onto the windows and also to drain away water flowing down the windows.
A photo from when the studio was being built:
The house has solar heating and solar electricity.
With the stairs going from the floor of the house, to the top and being capped by a sky-light, and also a south facing window (or two) at the top of this “column”, I was reminded of the Potton Lighthouse, with it’s “wind catcher / light funnel”.
I’m wondering if these windows could be an automatic, intrinsic way that the house heats and cools itself down?
Below is a screen shot from a PDF about the Potton Lighthouse.
In late Feb 2012 I dropped an message to www.newformenergy.com (via their on-line enquiry form) for a call to chat over the Silver Spray project.
Photovoltaic Thermal (PVT) is relativly new, but regarded as the most efficient at year round producing electricity and hot water.
” A well insulated 200m sq. house would need a 4kWp system costing around £20,000 installed, including a heat pump and hot water cylinder.” Homebuilding and Renovation magazine.
Supplier: www.newformenergy.com, where they claim:
So a combined system:
The Potton (now owned by Kingspan) Lighthouse project looks stunning.
I’m wondering if this could be flipped so the flat face has windows and faces the sea. Also make it thicker / deeper from front to back.