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2.25 kWp of PV installed

By Chris Newman July 18th, 2011

P1030772  The Government launched the Feed In Tariffs last year. This means that householders can generate income from electricity-producing technologies above and beyond the actual savings to themselves.  I’m not going to go into the pros and cons of the actual scheme here but just give some information about my new PV system (that photovolatics – i.e. panels for generating electricity).Since there will (hopefully) be some building extensions around the house, thus restricting scaffolding, and the internal walls are back to brick (so cabling is easy), we decided to install our PV system early.  Oh, and the summer is here so might as well start generating now rather than in the autumn. We’ve gone for nine 250W Sanyo HITE01 panels.

P1030777These are at the more expensive end of the solar panel range but offer higher outputs per unit area and we don’t have the largest roof to play with. The inverter is an EverSMA 2500HF. 

 

To start from the beginning and very basics…

The panels sit on the roof.  A frame is fixed through the tiles onto the roof rafters and the bolt holes sealed. The panels sit on the frame. The panels are pretty light – our 9 panels weigh less than two of me.  This means that the additional weight on the roof is not a worry.  In actual fact as there is a gap behind the panels due to the frame holding them off the roof there is actually greater risk of lift.  The gap is partially there to help them cool as heat reduces their efficiency.The picture below is just after 7.30am so shading is not going to be a problem!

The panels produce DC electricity and are connected to an inverter which we have situated in the loft space.  Ours is bright yellow so cannot be missed.  The inverters primary function is to convert the DC current to AC.  It also manages changes in the DC input to optimise the output and records lots of statistics for us.The output AC current from the inverted travels down to the a generation meter and into a dedicated RCBO on the consumer unit. It could go into its own MCB on an RCB protected side of the consumer unit instead. Don’t worry if none this makes sense as the installer will do everything and provided you with relevant certificates before they finish.

We will get paid for everything we generate (~43p per unit), what we are deemed to export (~3p per unit) (deemed to be 50% of that generated) and won’t pay for what we actually use of that which we have generated (~13p per unit not bought).

Over the first 9 days I’ve averaged just under 10kW a day or around £4.50 a day in revenues/savings. We do have very long days at the moment although it has been pretty inclement since the panels went in.

P1030775So what can we expect to generate from our system?  Somewhere between 1,850kWh and 2,000kWh or around £1,000 a year in payments from the Feed In Tariff and electricity savings. So now my challenge is to see if I can get our annual electricity use down to near what we will produce.The first year of the Feed In Tariff was a particularly sunny year and first indications are that most systems significantly outperformed expectations.  My Dad’s did by over 30%.Parity Projects independently calculate expected returns for you as part of our Home Energy Masterplans where appropriate.