‘I turned into a solar nerd’: money and fun were the unexpected benefits of

An abiding memory of a day in August 2010, the first time my solar panels were connected to the grid, was of the builders downing tools and watching the electricity meter whiz round backwards.

It was a sunny day and they were supposed to be finishing the plastering and insulation, but the novel sight of the old-style electricity meter in reverse was too entertaining.

For the previous few months we had been refurbishing my new home, a 1930s bungalow, with some of the many “green” improvements that I had been recommending to Guardian readers during my 16 years as environment correspondent. Friends said I was “putting my money where my mouth had been”.

It proved more difficult than I imagined because there were so many options. In the end we settled first for super-thick insulation – three times the government recommended minimum – and a green roof over the flat roof extension for extra insulation. To add light to a dim interior, four triple-glazed skylights were built into the roof. We converted a double garage into a library, reinforcing the flat roof, and found space to install 10 solar panels facing south.

Of course, the electricity company soon rumbled the fact my meter was going backwards and dispatched a man in a fast van to swap it for a modern version that could only go forwards. He and they were cross.

Of all the “improvements” it is the solar panels that have been most beneficial, financially and for all the fun I have had out of them. The first cost – £12,000 for a 2.4kW system – was more than double the price a much better system would cost 14 years later. But the carrot for spending this hard-earned capital was that the government was prepared to pay householders 40p a unit for every kWh of electricity the solar panels produced – and that was index-linked and guaranteed for 20 years. This generous offer meant they paid me even if I used all the electricity myself.

In the 14 years since I had them installed, the panels have provided me with an income of more than £1,000 a year from the so-called feed-in tariff – plus, of course, I’ve saved on my electricity bills by not having to buy power from the grid. So I am in considerable profit with six years to go on the contract.

The fun bit is the solar gadget on my kitchen windowsill that tells me how much power I am producing at any moment. It is updated every 30 seconds, gives the daily and past monthly totals, and shows how much electricity I have produced in total since the panels were installed.

It has gradually turned me into a solar nerd. First, the surprising thing is that the panels provide some electricity even on the dullest, rainiest days. The best days are cooler sunny days, since my solar panels are more efficient the colder they are.

The record daily total for my panels is just over 15kWh – and this happened a couple of days in a row. That was in May 2020 at the height of lockdown, when there was brilliant sunny weather. But what made the difference to turn these days into record days, I have concluded, was that there were no aircraft in the sky and the international flights that frequently leave sun-blocking contrails over Bedfordshire had been grounded because of Covid-19. It cannot just be a coincidence, because while central England has had many sunny days before and since, and 14-plus kWh days have occurred every year, there has never been another 15kWh day before or since.

The worst days are, of course, in the middle of winter. On a dull day in December the total is sometimes less than 1kWh – often on a day when you would most need the electricity.

A sad moment came when next door decided to build a two-storey extension on their house to accommodate a growing family. It shades half the solar array in the winter months, when we need the electricity most, but surprisingly makes little difference to the annual totals of electricity produced.

Since my basic panels were installed, huge improvements have been made to solar systems. Modern solar panels now heat water as well as producing electricity, and the surplus, instead of going to the grid, is stored in a battery, thereby saving money after dark. Of course, you…