Several people have noticed, and asked me about, the solar panels on my house. I moved in last October, and they were my first priority. They really work: I turned off my gas boiler completely even before the equinox. Of course, we have had an unusual amount of strong sunlight this March and April, and as a household we try to be careful about the amount of water, especially hot water, that we use. But we can cope even in gloomier weather. Today, for example, has been overcast, so after our hot morning showers the water has remained lukewarm, but it’s still okay for washing up.

The solar panels only heat water. It is possible to get photovoltaic panels to provide electricity, but the general consensus is that PV technology needs to progress a bit more before these become a worthwhile investment. You need to have an awful lot of available roof space, all south facing, for PV to be effective. In the meantime, you can get your electricity from a ‘green’ supplier, the best of whom, in ethical and renewable terms, is Good Energy, www.good-energy.co.uk.

Solar technology is improving all the time, and different companies offer different ‘generations’ of solar collectors (the long tubes that make up the panels). You may want to do a bit of research on this, to see whether you want or need the most recent designs. I had solar panels on my previous property, too, and the technology has moved on significantly since those were installed in 2000. My new panels are noticeably more efficient. However, my solar water heating system still needs electricity to operate. There are other suppliers who include a small PV panel to operate the system, which seems a very good idea. One such supplier is Solar Twin, www.solartwin.com.

The price can vary dramatically, depending on the type of solar collectors and the nature of the installer – from under £1.5k to over £7k. There are supposed to be government grants to assist, but these keep getting suspended (see the story in The Guardian, http://environment.guardian.co.uk/energy/story/0,,2061739,00.html). I bought my solar panels from Solar Home Energy Ltd, www.solarhomeenergy.co.uk. I chose them because they have a ten-year warranty and promise good technical support if anything goes wrong. This had been my problem with Solarsense, www.solarsense-uk.com, the company who had provided my previous system. The system did not break down, but it did need regular servicing, and I found it was impossible to get anyone to return my calls or to send out a reliable and interested technician. Solar Home Energy also has a BSI kite mark for their technology, which provides certain guarantees. However, they are not cheap – although they offer significant discounts if you can advertise them, which is why I have one of their boards outside my house on the canal. To choose a suitable supplier, you could try the listings of the Solar Trade Association, at www.greenenergy.org.uk/sta/. But whomever you choose, someone is bound to tell you that they got a comparable system much more cheaply. Life’s like that.

I did not need planning permission for the panels, even though this is a conservation area. The council said that it was okay because they did not change the exterior of the property. Moreover, BANES is supposed to be committed to reducing carbon emissions, so they have no reason to want to object to such work. Solar Home Energy contacted the council on my behalf, and would have submitted the application for permission, if it had been needed. They would have passed on the council’s charge for the application to me, but would have done the paperwork as part of the installation process.

Installation, and the number of panels that you will need, depends upon your hot water usage and the orientation of your house. My previous house was south-facing in open fields, so the panels received every drop of sunlight that the good Lord provided. My current house is east-west facing, and the roofs are also overshadowed by other buildings during part of the day. Consequently, I had to have panels on both side of the house, and also required an extra set of panels, at additional cost. Nonetheless, I am impressed at how well the panels work, given that they only receive sunlight for half of each day.

You need time to get all the work completed for an installation. Initially a technical expert will need to assess your needs and work out how the installation can be done – where piping will need to go and so forth. The significant variables for the engineers include how many panels you need and where they should be positioned; the position of the panels vis-à-vis your hot water cylinder; whether you need connections coming from two roofs, or only one; and where those connections can run. All of this stuff follows existing plumbing routes, so shouldn’t involve significant alterations. However, you will need a new cylinder, because the solar panel heating uses a different technology, inside your cylinder. This is a pain if you’ve recently bought a new cylinder!

After the initial technical specs, there will be several other workmen traipsing through your house. At my previous house, there was roofing work to be done first, as the company didn’t feel confident about the existing tiles supporting the panels. Solarsense put me in touch with a roofer who was excellent, and also did some other work for me at the same time. Then there may be scaffolders. I needed scaffolding at the front and back of my house for the new installation, but in my previous house, where the architecture was different, it was possible to do it just with ladders. Then follows the actual installation, which need not be too disruptive. However, I would recommend getting the work done in the summer rather than in the winter, as there will be a lot of in-&-out, which is not a good idea if you’re trying to keep in heat. The installation of the panels and the piping requires people to work on the roof, inside the attic space and down to your cylinder cupboard. Then there is some additional plumbing work, which may be carried out by a different person, but doesn’t seem to take very long.

Heating starts to work when the panels reach a certain ratio warmer than your water, regardless of how hot your water already is; and it will stop when the differential between the heat of the water and the heat of the panels drops below that ratio. This means that the water can get very hot in mid-summer. There’s no way to store the energy, so if there’s no heating from the panels, your water will start to cool no matter how hot it may have been the day before. However, my experience at my previous house was that we could usually leave the gas boiler turned off completely for at least four months of the year, and did not need it for more than a little ‘top up’ for much of the rest of the year. Nonetheless, if you’re looking to save huge amounts of money, then I’m sceptical: the initial investment will take a very long time to recoup. But for me it’s worth it in terms of eco-guilt – especially knowing that the purchasers of my old house would probably not have installed solar panels themselves, but are now happy to recommend them to their friends.

However, solar panels are only a small part of the struggle to reduce carbon emissions from our homes. Insulation is also very important, and the council offers support for this via the HEAT project (www.heatproject.co.uk). You can also now get ‘clean burn’ wood burners, which are enormously efficient and are carbon neutral. I have one in my house, which means that we don’t need to use gas for heating except for an hour in the morning on days when it’s very cold and dark, and we need all the encouragement possible to get out of bed! Knights in Marshfield have a really good selection (www.knight-stoves.co.uk) and you can get sustainably-managed wood from the National Trust’s woodlands at Prior Park (01225 833422).

I would also recommend having a full environmental audit on your house. There doesn’t seem to be anyone local who does this for domestic houses rather than businesses, but Donnachadh McCarthy, author of ‘Saving the Planet Without Costing the Earth’, was prepared to travel down from London to audit my house, and his fee was very reasonable. He’s a lovely man – really helpful without being at all judgemental (http://www.3acorns.co.uk/).