Wednesday, 26 May 2010

Renewables

How about generating your own electricity? Unsurprisingly there has been huge interest, and this is expanding dramatically now that Feed-in-Tariffs (FiTs) were launched in April this year. Feed-in-Tariffs guaranntee you a premium rate for any electricity you export to the grid, thus greatly reducing payback periods. Indeed, it is anticipated that exporting renewable energy may become a profit centre for the householder. There are two main technologies suitable for home-brewed electricity:

Photovoltaics
Solar arrays, which are usually roof mounted, generate electricity in daylight. They have a fairly high installation cost - typically around £1.000 per sq.m - and the amounts of electricity produced are not that large - typically 100Wh/sq.m/annum. The electricity produced is DC and it needs to be converted to AC for use in the home and for export to the grid. This is done by way of an inverter and a two-way meter. The installation needs to be south-facing for effective use. There are many different systems on the market, including versions that integrate with roof tiles, so that you don't end up with a separate panel on top of a new roof.


Wind Turbines
Come in many shapes and sizes and, invariably, the larger the turbine the better the performance. The small, roof-mounted ones have proved to be very disappointing but 6kW wind turbines, mounted on a pole, can deliver up tp 5,000kWh/annum for a cost of around £20,000. Again, the system needs an inverter to tramsform the current and a two-way export meter. The success (or otherwise) of wind turbines is incredibly location-sensitive: you need good average wind speeds, and a site which is not affected by nearby buildings or trees - ideally somewhere out in the wilds.

No comments: