PV panels are one way to collect the sun’s energy

Solar energy can be collected in all sorts of ways: you can use it to heat water, you can have photovoltaic cells installed and generate electricity, you can have a sun porch and enjoy passive solar heating, or you can grow plants. Green plants use sunshine to convert water and carbon dioxide into carbohydrates… that’s how they grow and that’s photosynthesis. So, any plant cultivation you do means that you are collecting solar energy (and making use of a greenhouse gas, but that’s a whole other story) and it doesn’t require a bank of batteries to store it.

The trouble is that in temperate climates we experience seasons. Some periods of the year are sunny and some not, some are hot and some are cold, so our plants are not able to photosynthesise the same amount all year, nor do our solar panels generate the same amount of electricity. Here in the UK we are currently in the middle of summer… and a rather nice one too. The sun is shining and the fruit and vegetables  are growing well (at least they are it we give them some extra water). As a result there is every likelihood that, in our garden at least, we will soon have more produce than we can consume immediately.

Of course, an abundance in the garden means an abundance on the farm too, so seasonal produce is likely to be cheap at a time when we don’t really need to buy it. The answer is to stock up on the sunshine now, or at least the products of the sunshine, and keep them so that you can enjoy them later in the year. The best fruit and vegetables in this respect are those that can be stored as they are harvested – potatoes in paper sacks, beans dried in the air and stored in jars, onions hung in strings and winter squashes ripened in the sun then kept in the cool dark attic. However, many crops require a little more work.

In the middle of processing the apple glut of 2011

I posted the other day about bottling peaches, and ages ago wrote about dealing with the High Bank apple glut in 2011 (another is promised for this year). And, thus, I store the sunshine: bottling and freezing are the two main routes I take for produce that will not keep unprocessed. I know that many people make preserves, but we honestly don’t eat much in the way of jams and chutney, so it seems a waste to make these in abundance.

In many ways, freezing is the easier option – there is little chance of produce going off (unless your freezer fails) and there are many things that need no or little preparation before they are frozen. For example, raspberries can go straight into the freezer and, once defrosted, can be eaten as they are. Other things, such as runner beans or mange tout, require blanching before freezing (i.e. plunging into boiling water for a minute or two) and cooking when they are required, but these are very simple processes. Some vegetables and fruit do not freeze well: courgettes, for example. However, even these can be fried in olive oil and frozen for subsequent use in Bolognese, casseroles or on pizza.

But, part of me balks at storage that requires continuous energy input, so I really like being able to keep at least some of my harvest in bottles and jars. Of course, there is an initial high energy requirement for sterilising jars, boiling syrups and then heating the processed product in the jar to ensure that it keeps. But, it is possible to time these activities to coincide with the solar panels producing at their maximum rate so that we are using sunshine even more in the process. I only bottle fruit – there is too much risk of botulism with vegetables as they are much less acidic.  I use proper preserving jars and ensure that I follow the instructions (particularly minimum temperatures and timings) to the letter to prevent contamination and spoiling of the food and I find the whole process remarkably satisfying.

Once I have the dresser in the kitchen packed with jars of preserved fruit, I find myself peaking in just to enjoy the sight of all those bottles of sunshine that will be cheering many a dreary February day.