PV

Girton enjoyed a “first” on 1 February when a home in north Girton had photo-voltaic solar cells fitted. These roof panels covert sunlight into electricity which can be pumped into the National Grid if the supply exceeds demand.

The fitters arrived early on the chilly morning and quickly got to work.

Unpacking the components

The scaffolding had already been erected and the framework was quickly cut to size and erected:

The framework is assembled on the roof

Meanwhile the electrical connections were being made inside the house and the panels themselves hauled up to the roof.

The solar panels
The panels are carried up to the roof
The panels are quickly slotted into the framework

By 11am the panels were being fitted and the new meter installed, and by lunchtime the panels were already producing energy.

But this is February. Surely solar panels need rather more sun than we get in February? Well, of course the panels will not perform at their best. But the results for the first two weeks of operation are quite remarkable. The panels have already produced 62.30 kWh, an average of 4.8kWh each day. What does that mean? Well, a 100 watt bulb burning for 10 hours consumes 1kWh; a kettle consumes about 0.2kWh to boil a litre of water. Perhaps the most remarkable figure is that this 62.30 kWh represents a saving of 35.3kg of CO2as compared with conventional power-station production. And this is over a very dull and cloudy fortnight.

The red light indicates that power is already flowing into the system

The owner says “Our total energy requirement over the period was 102kWh, so the solar PV system is generating about 2/3 of our needs.” In the summer he expects to become a net exporter of power to the Grid and save something like 1.66 tonnes of CO2 each year. Even now there are times when he can watch the little ferris wheel on his meter happily going backwards.

Solar panels are a rarity at present, and therefore not cheap. The total cost was large, but nearly 50% was covered by a generous government grant. There was also a large amount of planning red tape to overcome. If the predictions are correct, these costs will be paid back in around 24 years. That may seem like a long time, and in mere financial terms is clearly a very long-term investment. But in sustainability terms the benefits are great, and as energy costs continue to rise it becomes a better financial investment too.

We hope to have an update in the summer, and shall run a full report after 12 months of operation.