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Solar PV in the first Garden City


The TTL blog had a cup of tea and a chat with Joanna Jefferson, one of the TTL Trustees, about her newly installed solar panels.  We were keen to get her thoughts on solar panels and the Garden City. So what have have you had done? I’ve had 3.96kw of solar PV installed on my rear, south-facing roof.  That’s the kind of solar panels that generate electricity.  It makes as much electricity as the house consumes.

Sounds pricey. It was quite pricey!  The whole system has cost around £9k, but I expect it to be up there, generating for more than 20 years.  The roof is almost perfectly orientated for a system and subject to no shade.  It’s possible to get systems cheaper, but I wanted maximum generation for the space I had, so I bought more compact, powerful panels.

Will that pay for itself then? Absolutely.  The return will come from the “Feed In Tariff” which pays me for every unit of electricity I generate and the “Export Tariff” which pays me for those units I don’t use and instead sell to the grid.  Also, I can use the solar energy for free whilst it’s being produced.  It should return on my initial investment within 8 years.  It’ll be generating for a good time after that.

So does your house only use the electricity you generate?  What do you do if it’s not sunny? There’s a technical answer to this question, but you’re probably not going to get it from me!  Basically, the electricity produced by my solar panels is at a slightly higher frequency than that available from the grid.  That means that when the panels are producing electricity, the house will draw on the higher frequency electricity as a preference over the electricity from the grid.  At night time, or when the house needs more electricity than is being produced, I draw from the grid like everyone else.

And what happens when you’re making more electricity than you’re using?


That’s when it gets exported to the grid.  The idea is that you try to use as much of the electricity as you can whilst it’s being generated to get the full benefit financially.  No more vacuuming in the dark – get the appliances on while the sun shines!

What about people who aren’t at home much during the day then? That’s me too.  I go off to work and leave the house ticking over.  In order that I could get the benefit of some of the electricity I was generating and exporting I had a seperate circuit fitted for my water tank’s immersion.  A diverter senses when electricity is being exported and sends this excess to the immersion instead of to the grid. Previously I’d heated my water using a gas boiler, but since this has been installed I’ve turned that off.  My water’s now heated for free – even at this time of year!

Sounds brilliant!  But I have to ask… you live in Letchworth, famous for it’s much debated Design Principles… so how did you get on with getting this approved by the Heritage Foundation? Good question!  My house is on the current list of “exceptional” homes in Letchworth Garden City.  I asked for permission for 12 panels and was initially told I couldn’t have that many, but that 10 might be fine.  I appealed.  The refusal was based on what is, in my view, a rather spurious rule that solar panels shouldn’t cover more than 50% of any roof plane.  12 panels was 60%.

So you challenged that and they gave permission for you to have 12? Yes.  Which was the right decision!  Although I would say that.  That particular rule needs to be revised or preferably removed urgently in my view.  The fact that the panels are on the rear of my property also helped my application.  I know some people don’t like the look of them, but they don’t bother me.  In fact I like the fact that they’re an obvious statement of low-carbon self sufficiency.

I feel for my neighbours on the opposite side of my road who have south facing roofs facing onto the street scene – they’re unlikely to be permitted solar panels at present.  That seems a bit short sighted to me as the panels are a temporary change to the building.  If a more discrete solution for micro-generation comes along that’s more efficient, then people will move onto that in coming years.

The assumption seems to be that solar panels will change the town for the worse, but that fails to recognise that climate change and fuel poverty will also severly damage our community and way of life.  It’s time we reverted back to some of the original Garden City values of a decent standard of living for all, in a way which is gentler on the planet.

You clearly think it’s important that micro-generation solutions are adopted then. Absolutely. I’d say that if the only thing putting a householder off is the thought that they won’t get permission from the Heritage Foundation, they should apply anyway.  I’ll happily speak with anyone who has had permission refused to see how the decision might best be appealed.  They should get in touch with TTL.

And if an appeal is unsuccessful? Where there’s real value in conserving a home’s appearance or a property just isn’t suitable for micro-generation, you can still support the green energy revolution by switching supplier to someone like Good Energy or Ecotricity.  You could also get involved with TTL’s Energy Group who are keen to start a solar farm co-operative.

Would you like to tell us who installed your system for you? Yes.  Letchworth resident and business owner, Colin Poulter of Green Systems Engineering.  Highly recommended!

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