Our very own solar system
One of the members of our steering group, John D Anderson, has recently installed solar panels (both thermal and PV) on the roof of his house. It wasn't cheap, but it was worth every penny, as John explains...
1 Preparation
1.1 We were first inspired by the Energy Show at Olympia [in 1970 I think] when we saw a little rotating machine like an anemometer, powered by the sun through a photo-voltaic cell. We thought, 'That is the future.' We saw them working on a considerable scale in Botswana from 1993-7; there, the sun powers telecoms and water-pumps, recharges batteries etc.
1.2 We researched the various options for reducing our carbon footprint. The Energy Saving Trust [EST] www.est.org.uk is the best objective source of information, pointing the way to many others. It has excellent fact sheets on all renewables.
1.3 We saw a small wind turbine at Slaidburn next to Dale Head church, a building which is entirely off-grid. We decided against wind energy for us. Our turbine would be too small, too hedged about with trees [which would cause turbulence] and too close to too many neighbours.
1.4 We saw a ground-sourced heat-pump in the new building of Watson Batty architects behind Marks and Spencer in Guiseley. We decided against a ground-sourced heat-pump for ourselves as it would mean taking up the floor and installing under-floor heating.
1.5 To be eligible to receive from the DTI a Low Carbon Buildings Programme grant for renewable energy installations www.lowcarbonbuildings.org.uk, we had to insulate all the walls, put 270mm of insulation into the loft, have double glazing, and install low wattage bulbs wherever practical. The nation-wide amount for grants has been increased from 2007; the amount per head, however, has been greatly reduced.
1.6 We consulted Mervyn Flecknoe who has solar thermal panels and photovoltaic panels. We visited Gibson's Mill, the National Trust's property at Hardcastle Crags, Hebden Bridge; this is entirely off-grid.
1.7 We got in writing a statement from the Planning Department of the Council that no planning permission was necessary as long as the solar panels did not project more than 100mm above the existing roof.
2 Decision
2.1 We decided that solar thermal panels for heating our water, and photovoltaic [PV] tiles for generating electricity would be the best for us. The latter decision was only possible because we needed to re-roof the bungalow. Otherwise we would have installed photovoltaic panels.
2.2 Mervyn Flecknoe's PV panels are fitted on top of a south facing roof. They were installed by Ecoheat [of Hebden Bridge] which is part of the Alternative Energy Centre there. We visited it; the exhibition seemed a little amateurish - but Mervyn was very pleased with what Ecoheat did for him. His panels [not tiles] for a 1.75KW system cost about £10 000 some years ago.
3 Finding the contractors
3.1 In our case, we needed a willing and efficient roofer to cooperate with the solar energy firms. We found one in Turner Bros, Slaters, of Baildon T 01274 584965 and 01274 427531. Bill Pringle of Turners proved to be a superb choice; he did all the work perfectly. We took another quote from a roofing firm recommended from a job they had done in our area: Pickles Bros of Leeds T 0113 2752620. They gave an efficient quote of about £2000 more than Turners.
3.2 The Energy Saving Trust has a list of approved contractors for renewable energy work. If you use a firm not on the list, you cannot get a government grant. We asked for quotations from On Tap Solar of Huddersfield www.ontapuk.com who were just starting up in the solar business; and from Solar Utilities of Rotherham www.solarutilities.co.uk: they both had the advantage that they said that they could do the PV and solar thermal work. Neither had much experience, however; though they may have now. Ecoheat of Hebden Bridge did not reply to our request for a quote.
3.3 We also got a quotation from Sundog of Cumbria www.sundog-energy.co.uk. They are on the EST list of accredited firms. They had done the work at Dale Head on the wind turbine and I had talked to them there. We were impressed by their experience, competence and youthful enthusiasm. Their prices were little different from the others. They do not do solar thermal installations. We asked to see PV tiles and talk to the users; after 3 months we had convinced Sundog that we were serious [they have 40 enquiries for every contract successfully let] and we finally were given details of a place in Barnard Castle to visit. The users said it was trouble free, but had no records of how much electricity the tiles generated: they had inherited them on their building, which they leased. We accepted the Sundog quote for £19128 [incl. VAT at 5%] for a 2.24 KWh system of tiles.
3.4 We had had Sunuser of Leeds [T 0113 262 0261] recommended for supplying solar thermal panels. They are not on the list of EST accredited firms, but the possible grant for solar thermal was only £400 and the lack of such a sum was not significant. We asked to see some of their work; someone in Baildon showed us what they had done 5 years ago; she was perfectly satisfied. Unlike Sundog, who only wanted photos and drawings, they sent an informed Sales Rep.; he was never pushy. We accepted their quote of £7812 [incl. VAT at 5%].
4 Installation
4.1 We agreed that the south facing roof would take the PV tiles, since they need all the sun they can get; any shadow on any part reduces their efficiency. The solar thermal panels were arranged for the garage: two on the east facing and three on the west facing roofs. Oddly, the two east facing panels have so far in 2007 generated more heat than the three west facing.
4.2 With three contractors I was expecting co-ordination problems. There were none. They all came exactly on time. Turners, the roofers, had to put on counter battens under the PV tiles to raise them a little to help dissipate the extra heat generated. Sundog had to arrive when the south facing roof was exposed; they did. Sunuser had to arrive when the garage's east and facing roofs were finished; they did.
4.3 The PV tiles are Mini-stonewold-compatible Redland roofing/BP Solar SRT40's. Each replaces four ordinary tiles. They interlock exactly with the Mini-stonewold concrete tiles. They generate DC current which flows down to a Fronius inverter IG20 in the garage to be made into AC current. This tells us, second by second, how much electricity we are generating: a few hundred watts during all daylight hours on a dull day; up to 2200w on a sunny day. A separate cumulative meter, Elster A110C, keeps an official record of all the electricity we produce, in order to calculate what we are to be paid. There are virtually no moving parts and a service contract is not necessary. Once the system is in place, an electrician has to come to link it into the main electrical system of the house and the grid. [His bill was £228] The grid operators have to be informed; they own the mains cabling system and need to know that a new generating station [!] is supplying current. In this area the usual one is NEDL/YEDL T. 0845 6024453.
4.4 The solar thermal panels are filled with pressurised antifreeze which is circulated by pumps positioned in our airing cupboard next to the hot water tank. There is also a pressure gauge, and a bigger tank than is normal in order to accommodate the pipe coil for the solar thermal heated water as well as that from the gas boiler. Moreover, the bigger tank stores a lot of warmed water which can be heated up very quickly by the gas boiler if necessary. In the loft is a small spherical expansion container to take up any excess pressure. In the garage is a meter which shows how much heat each of the west and east panels is producing, and what the temperature is at the top and at the bottom of the hot water tank.
5 Operation
5.1 Normally nothing needs to be done to either system. Neither should ever be turned off. All the systems are actuated by daylight, not sunlight; but they are far more efficient when the sun is out.
5.2 The weight of the heavier tank on the plinth in the airing cupboard means that the wooden plinth on which the former tank stood needs to be strengthened.
5.3 On the PV system there seems to be no important problem. At night the grid supplies all our electricity; the grid acts as a battery for us.
6 Costs and benefits
6.1 'Economy' meant originally 'management of the home or the environment'. It did not simply concern money. By this definition, the systems are very economical, saving perhaps 500 kg of CO2 a year. We used 2339 KWh of electricity 2005-6.
6.2 In money terms, the equation is more complex.
6.2.1 So far we seem to be using very little gas in the summer months: the gas boiler is only actuated for 10 minutes a day, 2100-2110, and then only if too little hot water has been provided by the system on a very cloudy day. The solar thermal system does not, however, supply any hot water for central heating.
6.2.2 We are paid 4.5p for every KWh we generate, even if we use it. This is funded from the Government's Renewable Obligation Certificates [ROCs] held by Good Energy, our generating firm www.good-energy.co.uk . We get a twice yearly cheque. We pay for all the other electricity we use. Good Energy estimates our usage of our own energy; they will not [yet?] supply an import-export meter as we are 'too small'. 'Good Energy' have topped the ethical lists for moral firms and have been open with us; but their electricity costs about 12% more than most others, since it is all generated by renewables. We are officially the 'John D Anderson Solar' generating station!
6.2.3 Gas and electricity prices will go up - and up; as they do so, our system becomes more and more cost effective.
6.2.4 The value of our house is increasingly enhanced, since the Home Owners Information Packs now must include details about energy performance. Mr Stephens of Dacres Estate Agents in Baildon has said that he cannot yet estimate the extra value that solar panels and tiles put onto the price of a house. He says that the systems are so new that he needs to wait until we can show cost savings etc. The systems should be effective for 25 years, but no one knows how much longer than this they may last, since none has been installed that long.
6.2.5 The energy pay-back time is three years. This represents the energy taken to manufacture the panels calculated against the energy generated by the installation. Solar installations therefore save much more C02 than is needed to manufacture them. This is important for global heating.
6.3 Another energy generating firm used by Mervyn Flecknoe is NPower Juice; this supplies 'green' electricity at the same rate as electricity generated from fossil fuels. NPower Juice estimates how much electricity Mervyn exports to them and sends him a cheque four times a year for this, payable at the standard rate per KWh. They have said they will supply a free 'export-import' meter to measure exactly how much his PV panels export to the grid. This is clearly much better than an estimate - but the estimates are often generous. Mervyn says that in Germany domestic producers are guaranteed four times the standard rate for 20 years, which dramatically changes the financial basis of all these arrangements. He generates 1400 KWh per year, saving well over 500kg of carbon dioxide emissions; he also uses 3000 KWh from the grid; so in Germany he would have no electricity bill at all!
6.4 We have informed our house insurers of our solar installations. They said that they were happy to include them in our insurance for no extra cost.
6.5 The Low Carbon Buildings Programme offers grants on the conditions outlined above. We have received £2500 towards the cost of the PV array. I applied electronically at 0900 on the day the grants were offered; by 0930 I had confirmation of the grant.
7 Conclusions
We have become more attuned to nature: we notice and care more how much the sun is out; we notice and care more how much electricity we are using. This valuing of natural processes is in the long run perhaps the most important result of installing solar systems.
We feel that there should be as many electricity generating stations as possible: PV, wind, tidal and wave. These will distribute both electrical and, by extension, political, power more democratically. On a big enough scale, renewable generators obviate the need for nuclear power stations and can lead to the phasing out of all generating stations powered temporarily and dangerously by fossil fuels. Each station, linked by the grid, will back up the others. We could have a truly national electricity supply.
John D Anderson