Solar Panel Guide Discussion

keith_r59

If anyone is interested, The Guardian is running a competition to win £16k worth of solar panels for your home.

http://www.guardian.co.uk/environment/competition/2011/sep/07/solar-panel-competition

The competition closes at 23.59 on 14 September 2011.

zeupater

Studlea_Phatt_Katt wrote: »

The basis is that the majority of our electrical consumption is during daylight hours. Evening tends to be TV and a couple of lights only. Daylight hours all the heavy consumption appliances etc. We are happy to operate appliances in sequence, rather than simultaneously so as to maximise consumption of solar.

The whole building is well insulated, and the office working area heating is low consumption underfloor heating, so 1kw production in winter would more than cover it, consumption is 500w. In fact, after it's been on an hour or two, the room is warm and stays that way all day.

We are on a decent'ish fixed rate tariff, and the full year Dec – Dec last total consumption was 5007.5kwh, at a cost of £607.43. On average then, 13.7 kwh per day, of which I am guessing, 2/3rds is consumed during daylight hours. If we take a conservative average daylight hours as 8, and an average production from the 3.51kwh system as half, say 1.75kwh, then the system will likely deliver all of our daylight hours consumption, particularly if we are mindful to use appliances in sequence as stated above. So I guestimate the savings will be between £100 & £225 annual savings.

Hi

The above post seems to confuse kW, kWh & kWp .... anyway, a 3.51kWp system will not average 1.75kW of generation.

Using a simple calculation is to divide the 3000kWh.y/8(your Av)/365 is 1.02kW average (yours). However, as Gismosmum states, the majority of this production is in the summer so you will find that you will generate on average over five time the energy per day in June as you would in December. The problem with solar pv is that the source is not dependable, so the figures banded around are just averages. Even in summer you will have a range, yesterday we produced around 6kWh and the best this month so far around 21kWh giving a MTD average of 12.1kWh/day, so you must understand that in the winter months you will have days where you will be bordering on no production at all and others where you will be exporting a considerable excess for a couple of hours.

Your intent to use the appliances sequentially is exactly what is needed, you will find that most with systems already do that and it is already factored into the £100 figure. It is my strong belief that you should reduce the higher end of your guestimate by £100 in order to not be dissappointed with your actual savings, so base the range on £100 to £125 per year.

HTH
Z

zeupater

keith_r59 wrote: »

If anyone is interested, The Guardian is running a competition to win £16k worth of solar panels for your home.

http://www.guardian.co.uk/environment/competition/2011/sep/07/solar-panel-competition

The competition closes at 23.59 on 14 September 2011.

Hi

I do hope that the T&Cs are incorrect. Reading them they seem to describe the £16k as being the value of the system and point 9 includes that the winner will be "liable for all and any costs associated with the Prize, including without limitation, the installation, delivery and any other related costs." ... which could suggest that design, delivery, installation, scaffolding and liaison with the DNO etc. are not included .....

HTH
Z

KevinG

zeupater wrote: »

However, as Gismosmum states, the majority of this production is in the summer so you will find that you will generate on average over five time the energy per day in June as you would in December.

This site shows solar irradiance by month and location: http://www.efficientenergysaving.co.uk/solar-irradiance-calculator.html. It shows that, for me, June is just over 8 times as much as December. I am using these figures to monitor my monthly output against expected, based on my yearly estimate, and so far it seems pretty accurate.

zeupater

KevinG wrote: »

This site shows solar irradiance by month and location: http://www.efficientenergysaving.co.uk/solar-irradiance-calculator.html. It shows that, for me, June is just over 8 times as much as December. I am using these figures to monitor my monthly output against expected, based on my yearly estimate, and so far it seems pretty accurate.

Hi

Try this .... http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php ... it's much better and customisable for your particular setup ... you can also build a shade model for your particular array. Use the 'CLIMATE SAF PVGIS' dataset for a more accurate figure for your location ....

HTH
Z

mickyduck

zeupater wrote: »

Hi

Try this .... http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php ... it's much better and customisable for your particular setup ... you can also build a shade model for your particular array. Use the 'CLIMATE SAF PVGIS' dataset for a more accurate figure for your location ....

HTH
Z

Hi using this site I locate my property at 14'18" N and 47'7" W. Cannot seem to get this into the SMA monitoring application for it to calculate my predicted output, still says "manual" entry? Any smart ideas?
Thanks

zeupater

mickyduck wrote: »

Hi using this site I locate my property at 14'18" N and 47'7" W. Cannot seem to get this into the SMA monitoring application for it to calculate my predicted output, still says "manual" entry? Any smart ideas?
Thanks

Hi

Smart idea would be to check the coordinates .... to me that means that you are in a boat somewhere above the mid-atlantic ridge and that's definately outside the dataset range of PVGIS and not near any city in SMA's SunnyDesign software (if that's the SMA software you mean) .....

:shhh: Don't post your exact location coordinates here or everyone will be around for a :coffee:...

HTH
Z

mickyduck

zeupater wrote: »

Hi

Smart idea would be to check the coordinates .... to me that means that you are in a boat somewhere above the mid-atlantic ridge and that's definately outside the dataset range of PVGIS and not near any city in SMA's SunnyDesign software (if that's the SMA software you mean) .....

:shhh: Don't post your exact location coordinates here or everyone will be around for a :coffee:...

HTH
Z

No problem with the tea....
This is what the PVGIS gives me

Location: 51�14'30" North, 0�44'9" West, Elevation: 69 m a.s.l.,

Thanks

Solar radiation database used: PVGIS-classic

Nominal power of the PV system: 4.0 kW (crystalline silicon)
Estimated losses due to temperature: 7.4% (using local ambient temperature)
Estimated loss due to angular reflectance effects: 3.2%
Other losses (cables, inverter etc.): 14.0%
Combined PV system losses: 22.9%
Fixed system: inclination=24�, orientation=0� MonthEd Em Hd Hm Jan 3.511091.0733.2 Feb 5.991681.8451.5 Mar 8.692692.7284.4 Apr 13.103944.23127 May 14.604544.83150 Jun 14.904464.98149 Jul 15.104695.10158 Aug 13.704254.61143 Sep 10.503153.44103 Oct 7.032182.2469.5 Nov 4.361311.3540.4 Dec 2.6883.10.8225.3
Yearly average 9.54 290 3.11 94.6 Total for year 3480 1130

mardycow

I am very interested in these solar pv panels, Had a guy from Carbon Legacy come out yesterday to quote me for about 13 panels, according to his figures he reckons if i spend £10,500 ish i would earn about £1700 pa from the generated and fed back electricity. Apart from all the previously mentioned ethical and political issues, does this seem like a good deal and has anyone any knowldge of this company or a better one?

digitaltoast

Cardew wrote: »

No I don't think so.

For a 4kW system the UK average anual output would be in the region of 3,400kWh per year(850kWh per kWp)

If it were possible to increase that output by 10% that would be an extra 340kWh pa which at 43.3p/kWh would be £147.

Mind you I have no idea how they increase output by 10% - unless they move the house and PV system to Cornwall;)

Ah, but I thought the actual "fed back in" tariff was lower than the "use it yourself" payments?

Anyway, talking of selfbuilder, they've got a PV Special this week:
http://www.selfbuilder.tv/index.php

Again, I'm not convinced of some of the numbers bandied about in the show. If you have 15 mins spare I'd be interested to see what you think.

EDIT: Just seen this: http://www.bbc.co.uk/news/science-environment-14842720

The UK has formally joined forces with a US laser lab in a bid to develop clean energy from nuclear fusion.

Unlike fission plants, the process uses lasers to compress atomic nuclei until they join, releasing energy.

THIS is what we should be spending the £8.2bn PV bribe on, not arsing around with glittery pointlessness.