… Energy saving
… Resource efficiency
… Renewable energy
… Water efficiency
… Out of Our Back Yard: Growing, recipies, local producers etc.
… Handicrafts
A reference guide to see how other's are tackling something you might like to try, or would like more information about. The stories may have contact details so you can ask for advice!
If you have any stories and experiences to share please get in touch.
You can download all the stories in one document here:
Renewable Energy Stories
Stories so far ...
Not so hard a winter – introducing wood pellet heating to Gulworthy Church
Solar Thermal Heating System successfully installed! … So far so good!!
Our solar water heating panel, one year on
Solar PV system successfully installed – another local example
One Year On … a years PV experience for the Dennis's
Not so hard a winter – introducing wood pellet heating to Gulworthy Church
About 7 years ago, the congregation at St Paul’s Church, Gulworthy, realised that their ancient storage heaters were taking a lot and giving nothing. Portable radiant heaters and rugs were tried but did very little to help. So we wondered about renewable energy.
Inspired, advised and helped by the Tamar Valley AONB, we visited a farm where a wood chip boiler supplied not only the farmhouse but two other houses nearby, by piping the hot water through insulated trunking set into the ground. After our return home we entered into discussion with our immediate neighbours, a primary school and parish hall. We proposed that a wood chip boiler be located at the school and the water trunked via the church to the hall. The wood chip could be supplied by our local timber yard at Bowrish, Crease lane, who would source the timber locally and feed the wood store directly from a mobile chipper very economically. After the initial discussions the hall committee decided that they should spend their funds on a new roof.
We invested a lot of money in a new water fed radiator system inside the church while the technical details of the supply were being investigated and the required permissions sought from the church authorities. Sadly the plan foundered at the last minute, a new school governor and new officer at Devon CC not having the same view as the previous incumbents.
By this time we had also received promise of some grant funding towards the project and further applications were in the pipeline. Inevitably we now had to decide how to provide the hot water. There is no gas main within economic reach and the price of oil was dramatically increasing. Further, if we did not use wood we would lose the grant funding and have to foot the cost of boiler and installation ourselves. Wood chip was no longer an option as the space for storage at the church is inadequate. We were also very keen to cherish the environment and use wood. So wood pellets it had to be.
With the help of our architect and support from the church authorities for this forward looking venture, permission was given for the boiler to be installed in a timber ‘pod’ outside the church, this measuring 4.5x2.5x2.2m keeping the ‘pod’ roof line below the church window. With much excitement a 50kw Austrian boiler and canvas 3 ton hopper were installed and connected to the radiator system and we watched the engineer do the first test firing. So we had the warmest Christmas in church in 2008 for a long while.
Initially we had some difficulty in getting a supply of pellets, a new pellet supplier near Bodmin suffering teething troubles with his new business. Also, as the pellets should be blown into the hopper, it proved a problem for him to get his lorry close enough, and an adaption to the ‘pod’ is being made to enable easier loading. The boiler runs completely automatically and very efficiently, particularly after the first few months and adjustments by the engineer to help suit our needs. 2kg of pellets = heat from 1ltr of oil making running costs a bit cheaper. Ash only needs emptying about every three months and boiler service annually. So far we are delighted with the system. Wood pellet boilers small enough for a large house are now being made, so if you have the space and are considering a new boiler, the wood pellet system may be for you.
Alan Fox. Secretary to St Paul’s Church, Gulworthy, PCC.
01822 833489.
Solar Thermal Heating System successfully installed! … So far so good!!
"We have just had a solar thermal panel installed. It is made in England and a design that makes it work even off-grid. It has a small solar PV panel that powers the pump and recharges the batteries that run the control unit. It has only been running for three days and with the good weather we're having at the moment, is probably the best it will ever be. We had been using an immersion heater for all our hot water. As a means of getting energy into water it's pretty efficient but much energy will have been lost in the grid to get it from source to the house.
I began by saying 'batteries' but because a rechargeable battery can only by cycled about 600 times this panel uses supercapacitors to store the power for the control unit because they can be cycled 500,000 times.
The frame of the panel is aluminium but this comes from Norway because they use hydroelectric power in the factory making aluminium sections. The pump is made in the UK, and I believe the rubber tubing might also be made in the UK.
The 'rubber' tubing is the secret behind the design because being flexible, it is frost proof. This means there is no heat exchanger and no antifreeze. The water passing through the panel is the same that will come out of the taps.
The first day we had it the weather was cloudy and misty so I was not surprised that there was not much heat but there was some. The immersion heater would take the tank up to 54C at the top and 18.6C at the bottom. We only know this because the control unit shows water temp in the panel, the top of the tank and the bottom and for the first day the panel wasn't working. The tank just got colder through the day till I phoned the supplier who asked me to check the pump. It hadn't been primed correctly but after removing the outlet and sucking on the pipe till I got a face full of water, it was all systems go.
Now remember that it was cloudy and misty all day yet the panel was at 57C and the tank, when it all finally started working at 2pm, had cooled to 40C at the top and 20C at the bottom. While the system still could not raise the water temp at the top above about 33C, the temp at the bottom was 26C when it finally went off at about 5pm. Remember that the immersion heater would never get it above about 20C.
But then the sun came out! Over the following 3 days with the panel cooling to about 15C at midnight, the maximum temp of the panel has been 82C, the top of the tank 65C and the bottom of the tank 56C. At 7pm this evening, the panel, having been in the shade since about 6pm, it has cooled to 37.6C but has left the tank at 60.5C at the top and 56.2C at the bottom, way above what the immersion heater could have done.
A thermostatic mixer valve prevents scalding water from reaching the taps and if you fear for the durability of rubber tubing, it is actually silicone piping used in the food industry so many of the ingredients in processed food you buy will have passed through similar tubing.
Maintenance? Hardly any! The virtually unbreakable double glazed polycarbonate panel might need a wash once a year and an annual check for leaks would be sensible. Cost? About £2,500 but a grant for about £400 was available. You would need to check the current situation regarding grants. This link (http://www.energysavingtrust.org.uk) may help. Then you have to decide if you want to have it installed or you feel brave enough to do it yourself.
If interested in seeing it and you live in the Tavistock area, just let me know or phone me on 01822 820345.
Adrian Hepworth
Our Solar Water-heating Panel, One Year On ...
In 2010 we bought a Solartwin hot water panel. It was the ingenious design and the thoughts behind its construction helped us choose SolarTwin. It’s made in the UK with most components also sourced in the UK. The aluminium extrusions that make up the frame came from Scandinavia because the smelting plant and factory is powered by hydro-electric power, so reducing its carbon footprint.
Its design, using silicon rubber pipes, means freezing in winter isn't a problem. There is no antifreeze in the system so no repeated top-up or replacement. In fact the water running through the panel is the same that comes out of the taps. The pump and control system are all powered by its own PV panel, it runs completely off-grid and requires no maintenance except perhaps wiping clear of leaves etc every few years.
Since English sunshine is not that reliable, we use a back up immersion heater to top up if the weather is cloudy. The time switch allows this to come one for an hour in the morning and an hour in the evening. An immersion heater is the most efficient way of heating water with electricity. The elements are completely surrounded by water so there can be no loss from heat escaping before it gets to the water. If the water in the tank is hotter than the immersion heater thermostat, then it won't switch on.
The panel supplies all the hot water in the house, from hand washing and dishwashing, to showers and baths. We don't have a dishwasher and the clothes washing machine has its own heater.
We get all our electricity from Good Energy who promise that 100% of their supply is from renewables, either wind power, hydroelectric or tidal. It is Good Energy that own the Delabole wind farm and recently replaced several old turbines with newer larger ones. They buy in hydroelectric from other generating companies in the UK: possibly even that at Mary Tavy.
We were aware that we would be paying a premium for 100% renewable supply but gambled on Good Energy holding their prices when other companies are forced to raise their prices in line with rising oil and coal prices. I tried getting a comparison from Uswitch website but without success.
One useful thing about bills from Good Energy is that each shows a comparison with the same period a year earlier. Unfortunately my filing system has failed me and I can only find the last 3 quarters but these are very interesting. The first bill is from February this year and is the highest because it includes Christmas when there are usually about 10 people here for a week, so heaters and electric showers get used. Normally electricity is just for light and cooking. The central heating is only on for that Xmas week/fortnight and we use wood fuel for the rest of the year.
The figures:-
• Initial cost of panel £2700 to include fitting kit, PV panel pump and control systems. Fitting cost about £500 so a total of about £3300.
• Average daily power - consumption during 3 mths to Feb 2010 was 24.9 kWh/day.
• After fitting the panel - consumption during 3 mths to Feb 2011 was 17.3 kWh/day.
• Reduction of 30%
• Average daily power - consumption during 3 mths to May 2010 was 24.9 kWh/day.
• After fitting the panel - consumption during 3 mths to May 2011 was 13.6 kWh/day.
• Reduction of 45%
• Average daily power - consumption during 3 mths to Aug 2010 was 16.3 kWh/day.After fitting the panel - consumption during 3 mths to Aug 2011 was 12.3 kWh/day.
• Reduction of 24.5%.
Maintenance costs over this time = zero.
To do a cost comparison is not easy because the bills use a mix of actual and estimated figures during those quarters which will have been corrected for following quarters. The average power usage should not vary as much but a truer comparison could be made over subsequent years.
Current cost of electricity from Good Energy is 14.22p per kWh. Using the latest prices and the last quarter’s average works out at £1.84/day including their standing charge of 9p/day. A 30 day month would cost us £55.20
During these periods we have still been replacing a few remaining incandescent bulbs but the bulk of the saving must be because of the panel. Our usage will not have changed that much. Using cold water for short washes or soaking dishes will have made only a small saving.
Our plans are to generate some of our own electricity but because of the amount used/wasted in the losses within the national grid, we would prefer to use any we generate on-site; but then storage becomes a problem.
If interested in seeing it and you live in the Tavistock area, just let me know or phone me on 01822 820345.
Adrian Hepworth
Solar PV system successfully installed – another local example
Mike and Jenny Dennis, both members of the TT Energy Group, have had photovoltaic panels installed during the first week in July 2010. With an array of 18 x 215w panels Mike and Jenny have the capacity to generate 3.87KW. Before and after photos can be seen below!
We’ll provide the full story in Transition Tavistock’s August newsletter.
They are going to maintain records of the amount of energy generated, how much has been exported to the grid and savings in other fuel use to calculate the overall benefits gained. These can be shared once there is sufficient data to make meaningful comparisons!
Background facts on the Installation of the Photo voltaic panels
The roof faces 160 degrees with a pitch of around 50 degrees.
The roof space is 55m2 on an 11m length and 4.95 length from ridge to eaves.
The system specification:
• 18 Kyocera 215W solar PV modules (3.87KW)
• Mounted with stainless steel roof hooks to aluminium solar rail
• Cables hidden under facia board
• Steca 4KW grid tie inverter
The inverter, FIT (Feed In Tariff) total generation meter and the import/export meter are installed in the garage.
Capital cost approximates to just over £4000 per KW
Projected annual output based upon the Government’s Standard Assessment Procedure 2005 is 3096 KWH per annum. Because Devon and Cornwall receive appreciably more solar radiation than the national average, most installations in the South of the UK generate around 900 KWh per KW of installed capacity annually rather than the 800 KWH as specified in the SAP 2005. However, the performance of solar PV systems is impossible to predict with certainty due to the variability in the amount of solar radiation (sunlight) from location to location and from year to year.
The FIT tariff commenced on 1st April 2010 and pays 41.3 for every unit generated. This is fixed for 25 years but for installations in later years the rate will be lower. There is an additional small sum for each unit exported to the grid and we also benefit from a reduction in our electricity bill as we use the renewable energy generated. We also expect a reduction in our gas bill as we will be using electricity to power our immersion heater instead of gas.
Based upon the national averages, the projected annual income was suggested as £1450 per annum. This would give a payback period of approximately 10.8 years. However, I hope that I will be able to achieve this within a shorter time period. Details on estimated progress towards meeting this target can be provided in a future update when more data has been collected.
If you are interested in knowing more contact Mike on 01822 618142
One Year On … a years PV experience for the Dennis’
Following the reports on the completion of the installation of photovoltaic panels on our home last year, I agreed to report on my experiences after a full year of operation.
The total kilowatt hours generated were 3338 kilowatt hours (kwh). Of these, 2712 kwh were exported to the grid. This means that we used 20% of the energy generated. It revealed to us that we used a significant proportion of our electricity in the evenings so we are still paying electricity bills but our monthly payments to the utility company has reduced. The indication is that if we were able to store all the electricity generated for later use we would still have more than enough for our needs. There have been lifestyle changes following our examination of how we use the electricity: a) except in exceptional circumstances we only use the washing machine when there is adequate kwh being generated; b) we now tend to cook our main meal at midday rather than in the evening when the sun has moved off the panels; c) we heat the immersion water heater by electricity rather than gas if generating approximately 3kwh for a period of even 10 minutes.
The average daily amount generated is as below:
July 9.7 January 4.5
August 9.5 February 4.0
September 9.7 March 11.7
October 9.0 April 13.4
November 5.5 May 11.0
December 4.9 June 12.9
This makes the point that it is the amount of light with lack of cloud rather than the amount of heat in the sunshine that provides the best results as April produced a higher daily average than the traditional summer months.
I had hoped to indicate the top ten of the individual high generating days but as I was away for parts of May and June , there were a number of weeks that I was only able to calculate an average generation amount. However, of those days that I was able to measure individually, the top days and amounts were:
June 3rd 22.6 April 21st 20.3
April 28th 21.9 Aug 10th 20.1
May 2nd 21.1 April 15th 20.0
April 19th 20.7 April 7th 19.9
April 17th 20.3 April 25th 19.8
Although the reasons for opting for a PV system were not purely financial, a question frequently asked relates to the pay-back period. I can report that I have received 4 payments from my utility provider amounting to £1586 . This covers the kwh generated and the additional payment for the kwh exported to the grid. On this basis alone, if subsequent years replicate the first year, the pay back period would be 10year and 7 months. However, taking into account reduced usage imported from the grid, (electricity usage was reduced by 30% on the previous year), I estimate that the payback period will be 9 years and 3 months.
There has also been a reduction in gas usage compared to the previous year and part of that reduction will reflect heating water by electric rather than gas on occasions.
The system has performed much as the installer had led me to believe and after one year I have no reservations about the installation benefits. I am always happy to show interested parties the system and associated figures and can be contacted on mikedennis_uyk@yahoo.co.uk.
Here’s to clear skies (and hopefully sunshine) in the next 12 months. Mike Dennis
