EF members' installs - show us your work!

Something a bit different.
6kWp west facing roof integrated system.

This used GSE integration on a monopitch roof. Little details a good roofer helps with is things like bird guard in tile openings. This style of tile is notorious for nests if not blocked. The last picture was taken before the roofers had got the Windowlene out.

I was surprised the customer went for it. The array experiences 11% shading loss, has a low pitch at 18 deg, and faces west. Add all this together, and output is predicted at 4120kW/a. Uses an Eltek 4.4HE-T limited to G83/2 on commissioning.

Roof integration added to installation cost. However, from the customers viewpoint it still gave a better return on their money than leaving it in the bank.

The Solar King said:

However, from the customers viewpoint it still gave a better return on their money than leaving it in the bank.

Click to expand...

How do you count in the loss of capital.... as it can no longer be used.

In the bank - interest and still have the capital, here you've purchased an asset to give you an ROI. So you can't directly compare like with like, it's more like buying 20 year futures on electricity...

(p.s. one of my clients is an actuary )

We use the economic model in PVSol

This is a full discounted cash flow assessed over 20 years to calculate returns and payback. This can make our calcs look slightly less attractive. The discount rate is set at 5%. This represents the value or opportunity cost of the capital. It is like saying if you hadn't invested the money in the PV system, but left it in the bank you would have received 5% interest. This cost is included within the calculation.

The payback period is when the total capital cost is amortised by the FIT payments, Export payments and electricity savings taking in to account all the inputs including the discount rate.

Background inflation is set at 2.5% and fuel price inflation at 5.1%. This latter figure is based on DECC's forward projections of 2.6% above background inflation.

Inverter replacement is included as an operating cost at £40.00 a year. Panel degradation is set at a total of 15% over the assessment period.

Electricity savings are calculated from Generation, Property Electricity usage, and a usage profile.

For this particular project the Yield was 7.2% with a payback of 15 years. The Net Present Value of the investment is £2134.00.

We also provide a straight forward return on funds employed in the first year (revenue plus savings minus operating costs divided by capital cost). In this case 8.2%.

We give the following disclaimer:

"The financial analysis is based on standard VDI 6025 'Economic calculation system for capital goods and plants'. This is a dynamic model that produces a Net Present Value based on the inputs using a Discounted Cash flow method.

Please note the analysis does not constitute financial advice as covered by the terms of the Financial Services Act 1986 and is provided for illustrative purposes only. As already stated the performance of Solar PV systems is impossible to predict with certainty due to the variability in the amount of solar radiation (sunlight) from location to location and from year to year. The estimate is based upon the software's calculations and is given as guidance only. It should not be considered as a guarantee of performance or financial return."

Worcester said:

How do you count in the loss of capital.... as it can no longer be used.

In the bank - interest and still have the capital, here you've purchased an asset to give you an ROI. So you can't directly compare like with like, it's more like buying 20 year futures on electricity...

(p.s. one of my clients is an actuary )

Click to expand...

Internal rate of return.

take the total 20 year income and savings, minus the initial cost, divide by 20, divide by initial cost = average anuallised IRR % return after the initial capital has been repaid, so is as directly comparable with a bank interest rate as possible (on long term savings / something like an annuity / long term bonds etc)..... but you also get to keep a solar PV system at the end of the 20 years.

In my example Yield = IRR

A couple of our latest, don't have many of the cable bits (I know how disappointed you'll all be )

Bridgwater (1MW) is a bit older but its probably our most well known, Yorkshire Building Society (199kW) was probably the most difficult to date upto 5 storey's up and on slate on a metal tray roof and Grosvenor Farms (250kW) on fibre cement roof


Morrisons Bridgwater 1000kW

YBS Bradford 199kW

Grosvenor Farm 250kW

I drive past the YBS most days and have to say how good it looks, I thought to myself how hard that must have been to install and on to slate!

Some nice jobs there !

JD6400 said:

Some nice jobs there !

Click to expand...

Thanks gents, some significant pain aswell!

As we only really do commercial we don't often come across slate, let alone 5 storeys up, if I tell you I was expecting to get 5kW/gang per day and actually got 2.5kW/gang/day I'm sure you'll understand what I mean :willy_nilly:

One thing I would say though was we used 'Genius roof solutions solar flash' which was great and saved an awful lot of time and produced a really neat job.

have you done all of YBS projects? Peterborough also?

Yes Peterborough was a bit smaller 159kW

Nice work, just twigged who you are now

SibertSolar said:

Nice work, just twigged who you are now

Click to expand...

Haha hope your well Andy! Keep pushing Sumith we've a lot of orders coming up, picked up another 1.5MW this week!