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10,000 kWh in three and a half years


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At the end of November 2011 I had installed a grid tied 3kWh solar PV system using 12 Sanyo 250W HIT H Series PV Panels with each panel having an Enecsys micro-inverter.  My meter has just clocked 10,000 kWh so I thought I would share a few thoughts.  Note this system was installed in the southern UK, I would expect the yield from a system in the Philippines to be greater.

 

The system cost just over £13,000, I would have saved £1,200 had I gone for a single string inverter.  Shading of panels by neighbours trees meant micro-inverters were more effective.  I was told using one string inverter with one panel shaded the output from all panels would have been impacted.  I also liked the online monitoring available from Enecsys.  Enecsys has subsequently gone out of business and the online monitoring is no longer available leaving the limited display on the data gathering unit and the Electricity company meter my only performance data.

 

Year 1 (13 months) 2833 kWh

Year 2  2675 kWh

Year 3  2878 kWh

 

I have not had the panels cleaned and there has been no obvious decline in output.  They are installed on the roof at 30 degrees from horizontal.  Despite the bird crap falling on my car and windows seemingly having the adhesive power of superglue, nothing seems to stick to the panels.  A friend just coming up to 4 years of using solar panels has the same experience.

 

I managed to qualify for the maximum Government subsidy on each kWh generated and the income near enough matches my annual gas and electric bills.  Since then for new entrants the 25yr inflation linked subsidy has decreased by around 75%.  Given the decrease in panel costs I would still be tempted to have panels installed as and when I move to a new house (assuming the previous occupants had not already done it).

 

You can now get a unit that instead of diverting unused power back to the grid, first uses it to heat water in the hot tank and only diverts it back to the grid when the water is up to heat.  If installing a system now I would install such a unit and a large capacity hot tank.

 

If living in a house in the Philippines in an area likely to suffer from brownouts I would be tempted to have an off grid system for daylight powered roof space ventilation and some lighting, ceiling fans and mobile phone charging etc.  As well as a grid tied system to reduce air con and other electric costs, assuming grid tied was available.

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to_dave007

Do you know the breakdown of the £13,000 expenditure?  Split between materials cost and labour cost?  And prices of key material items?

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Ozepete

From the data you have this doesn't look feasible at all:

 

You received 8383KW over the past three years or an average of 2795KW per year!
Not sure what your net grid charges are in your country but based on my grid power rate here in Oz of Au$0.22c /KW.,  2795KW would be Au$615.00 per year.
Now converting your capital cost from 13,000 British pounds is AU$26928.00, it would take 43 years to recoup the capital investment alone.
So if maintenance, future component replacements and lost investment interest income were added, the whole thing becomes more ludicrous!

Edited by Ozepete
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to_dave007

From the data you have this doesn't look feasible at all:

 

You received 8383KW over the past three years or an average of 2795KW per year!

Not sure what your net grid charges are in your country but based on my grid power rate here in Oz of Au$0.22c /KW.,  2795KW would be Au$615.00 per year.

Now converting your capital cost from 13,000 British pounds is AU$26928.00, it would take 43 years to recoup the capital investment alone.

So if maintenance, future component replacements and lost investment interest income were added, the whole thing becomes more ludicrous!

 

Lady I met in Toronto had CDN $17,000 put on her roof.. fixed price contract..  with grid tie inverter.. and after 2 years operation she estimated 17 years payback at the $0.41/kwh the local utility paid..  without considering any cost of maintenance or repair.  Better than your numbers here, but not something to invest in for the financial return. 

 

I asked her why she did it, and it was clear she wasn't a tree hugger, and she wasn't in the industry, and she wasn't a techie..  and she said it was just her contribution to improving the environment.  She did not do it for financial reasons.

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Ozepete

This is the trouble with the solar industry, the marketing hype of these systems is nowhere near the reality.

People who don't understand the real issues of power production spend thousands egged on by unscrupulous scammers making hypothetical claims that they know are not realisable.

And as for the environmental issues.. BS.

In a real world the power consumed in the manufacture, installation and all involved before there is any solar power production, equates to many years of solar power input even before that impost is met, and economically it is a not viable in most situations where grid power is otherwise available!

Solar has a place but not in many of the ways it is promoted.

Edited by Ozepete
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From the data you have this doesn't look feasible at all:

 

You received 8383KW over the past three years or an average of 2795KW per year!

Not sure what your net grid charges are in your country but based on my grid power rate here in Oz of Au$0.22c /KW.,  2795KW would be Au$615.00 per year.

Now converting your capital cost from 13,000 British pounds is AU$26928.00, it would take 43 years to recoup the capital investment alone.

So if maintenance, future component replacements and lost investment interest income were added, the whole thing becomes more ludicrous!

 

You are correct, the only thing that made it worth doing was the ludicrous Government subsidy, guaranteed index linked for 25 years.  I had the money earning minimal interest and decided to play and was not too worried if I did not make a profit.  In fact because I am very likely to move house by the end of 2017 I definitely will not make a profit.  My income from the panels:

 

Year 1 - £1318.26

Year 2 - £1290.17

Year 3 - £1424.76

 

Shortly after my system was installed the Government halved the subsidy for new entrants.  The installers were making large profits and the cost of installations also dropped by a huge amount.

 

At the moment there has been no maintenance required.  The micro-inverters and panels are supposed to have a 25 year life before failing!  There are guarantees on parts and installation, but I am working on the basis they are not worth the paper they are printed on.

Edited by Chas
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Do you know the breakdown of the £13,000 expenditure?  Split between materials cost and labour cost?  And prices of key material items?

 

I originally decided not to include this data as it is now worthless.  I am also sure the figures were inflated.  As I mentioned above the subsidy halved a couple of months after my system was installed and from memory once that happened advertised prices for new installations also reduced by close to 50%.  So here is the breakdown of my installation costs, but I am pretty sure there are some big profits hidden in there for the installer.

 

Panels   £6425.32

Micro Inverters £2397.23

Roof Mounting Kit  £586.08

Electrical Items  £531.78

  i.e.  Consumer Unit, Cables, Isolator, Meter

Sundries £1143.68

  i.e. Scaffolding, Sister Rafters, Trunking, Delivery

Installation  £1463.96

 

VAT 5% £627.40

 

I also got quotes from two other firms, neither salesman gave any confidence that they knew what they were talking about.  One stating that the shading from the trees would not reduce the amount of electricity generated.  Both quotes were slightly lower and both would only offer single string inverters.

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