Solar Quote-Opinions?

Qyburn

Screwdriva said:

11 X 430W = 4.7mW - let's assume 4500 kWh of optimized annual generation (Check PGVIS for a more precise forecast). Using Octopus Flux incoming/ export tariffs below:

Assume you will consume 25% of 4500 kWh at a cost of 23p per kWh
Assume you will export 75% of 4500 kWh at a rate of 17p per kWh . 

I presume those are your own percentages and averages. Export equates to around 25% at the peak rate (which I can already see we wouldn't achieve). Import not so easy to guess, any number of three way mixes could give that same result, what mix do you have?

philng

It is interesting I am not being quoted the same generation as the equivalent panels x kwh. Unsure why that would be?

For example 2997 kwh generation from 9 x 4.73 panels so significantly less and some are quoting pie in the sky future price rises & generation predictions to show massive benefits in excess of £30k.

Also when comparing they are using total Energy bill which obviously includes the Standing Charge which will obviously remain and may even increase if I change tariff. They should only be using actual Energy use cost in the comparison.

Looks fraught with danger and trust and what is being presented. 

Qyburn

philng said:

It is interesting I am not being quoted the same generation as the equivalent panels x kwh. Unsure why that would be?

It will depend on location, orientation and slope of roof, and the degree of shading. Clearly the same panels won't generate as much in N Scotland as they would in Cornwall (or Greece). Our installer estimated  5,300kWh per year from an 8.1kWp array. The JRC tool estimated a bit less than 6000, and early figures suggest we'll be somewhere in between.

https://re.jrc.ec.europa.eu/pvg_tools/en/

For example 2997 kwh generation from 9 x 4.73 panels so significantly less and some are quoting pie in the sky future price rises & generation predictions to show massive benefits in excess of £30k. 

I have often thought and said that the solar industry is where all the dodgy double-glazing salesmen have gone. I had some crackers, one calculated payback assuming we were paying "a typical tariff" of 45p/kWh.

I wonder about panel specifications as well. What make are those "4.73" which I assume means 473W? I wonder how real that figure is.

Screwdriva

Qyburn said:

I presume those are your own percentages and averages. Export equates to around 25% at the peak rate (which I can already see we wouldn't achieve). Import not so easy to guess, any number of three way mixes could give that same result, what mix do you have?

Those were my actual #'s. No battery. It's easy to move % between import and export but the goal is to highlight the return on investment is very much there. 

philng said:

Looks fraught with danger and trust and what is being presented. 

Sadly, you're correct. It's the wild west out there and yes, there is a mafia element to it. 

Qyburn

Qyburn said:

Our installer estimated  5,300kWh per year from an 8.1kWp array. The JRC tool estimated a bit less than 6000, and early figures suggest we'll be somewhere in between.

Actually I'm wrong on pretty much all counts there, I must have been thinking of export figures rather than production. PVGIS annual estimate is 6,280 and June, July and August have all exceeded the estimates.