Solar PV Panels

penrhyn

shenleley wrote: »

Has anything been in the news about this recently?

Mass slaughter in the Middle East....bong.

Nuclear meltdown in Japan....bong

Red light flashing on Mr Ecomentals inverter ...bong.

themaverick1953

chrismarsden wrote: »

Read the Which? report online, not sure if you need to be a member, also on TV news Midlands this evening, and I have spoken with a local (our Mayor) who has them, and is VERY happy with the return, £850 in less than a year on a 2Kwp. They all reckon on 9 years return.
Tax free, gtteed Index linked FiT for 25 years. 41.3p whether you use or not, AND get paid for the export 3p. Paid to next occupier of the house.

Its a no brainer As I see it. I have just ordered.

Depends where you live, and a suitable roof etc. Get a Survey, Which said only one Co gave all the right answers, Southern Solar, so give them a try. Also had a very similar quote from M&SEnergy.

Fitting in April. But Tariffs may change in Apr 2012.

I am considering a system currently. Are there any calculators that take into account aspect (mine is 110 degrees) and is there a way of measuring roof elevation without going up a ladder ( I would assume my average 3 bed semi now extended to 5 beds is between 30 and 45 degs). Also not much seems to mentioned of savings. I currently pay £60 per month for electicity and according to the British gas website that is about 80% more than a typical house in my area. I am interested in how I can use the electircity during the day ( I am semi retired and theres someone at home most days). For example do you set s timer sdo that an immersion heater come son for an hour - the freezer goes off for 2 hrs say just before pruduction starts - can you use the hoover and the dishwasher on free leccy during etc etc day?

Cardew

themaverick1953 wrote: »

I am considering a system currently. Are there any calculators that take into account aspect (mine is 110 degrees) and is there a way of measuring roof elevation without going up a ladder ( I would assume my average 3 bed semi now extended to 5 beds is between 30 and 45 degs). Also not much seems to mentioned of savings. I currently pay £60 per month for electicity and according to the British gas website that is about 80% more than a typical house in my area. I am interested in how I can use the electircity during the day ( I am semi retired and theres someone at home most days). For example do you set s timer sdo that an immersion heater come son for an hour - the freezer goes off for 2 hrs say just before pruduction starts - can you use the hoover and the dishwasher on free leccy during etc etc day?

There are several other threads that discuss how much of the generated electricity you can use in the house. This is one:

https://forums.moneysavingexpert.com/discussion/2955406

Firstly the amount you save off your electricity bill is small compared to the subsidies(FIT)

The biggest problem in trying to maximise consumption from the panels is the unpredictible nature of the panel's output. It can be nothing one day, and 20kWh the next. During the day a cloud can drop the output dramatically.

The most widely quoted figure is that you will use 50% of your generated output, although people say that is difficult to achieve.

A ballpark figure might be to save electricity worth £100 a year - others think that is a high estimate.

However that is small compared to an income from subsidies of up to £1,500pa for the largest(4kWp) systems.

Any MCS installer should give you a written estimate with the size of system, cost and predicted annual output.

will-he-payitoff

It seems like a few of our neighbours have jumped onto this and have paid to have solar panels fitted to west facing roofs in yorkshire, wonder how long these will take to payback.

John_Pierpoint

There are some solar thermal units being fitted facing east or west on a new housing estate being built near me.
Probably eco bling to help get permission from woolly minded types on the planning committee?

Gizmosmum_2

will-he-payitoff wrote: »

It seems like a few of our neighbours have jumped onto this and have paid to have solar panels fitted to west facing roofs in yorkshire, wonder how long these will take to payback.

Depends on size of array, cost of panels and whether finance used, Southern Scottish installation on West facing roof will payback in around 11 - 12 years compared to 10 years for South facing. Depends on what you want whether it's worthwhile or not.

John_Pierpoint

Check the physics here, then make your own calculations, remembering to factor in an opportunity cost of the loss of interest on money invested etc.
Remember like buying anything physical that you expect to last 25 years, it is likely to require maintenance (inverter?), might suffer damage (Vandalism? 1987 hurricane? etc.). It might be beyond economical repair by then, and cost money to dismantle and replace (if worth it then). [The only thing electrical that I've got that has (sort of) lasted 25 years is an Austrian chest freezer in my garage, its not in the loft or outside in the weather.]

http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php

I've made some guesses about a West facing roof in Yorkshire and even with the ideal pitch (over 45 degrees) the not wonderful northern output goes down over 14 percent if the panel is turned 90 degrees to the West.

[BTW the term azimuth is used because it saves having to say South in the North and North in the South half of our planet, it means "direction of the equator"].

ccnp

Apologies if this has been covered but I haven't spotted it on a trawl through the lists

How does my house know to use the PV electricity ? I seem to remember this is based on voltage but my system is usually below the grid voltage when I look.

2nd; transmission loss. I opted to have the inveter in the garage because the roof space used to suffer dramatic hot/cold swings. The PV panels now cover 90% of the space and has vastly reduced this problem. There is a 15m run of 6mm 12v supply. I have found calculators that suggest reducing this to 3m by moving the inverter will improve the situtation by c. 10%. That is around 1 kwh pd avg (44.8p pd inc export) and I can see a case for doing the move. There would be more power into the house as well.

thanks for any suggestions or references

Jon_Tiffany

ccnp wrote: »

Apologies if this has been covered but I haven't spotted it on a trawl through the lists

How does my house know to use the PV electricity ? I seem to remember this is based on voltage but my system is usually below the grid voltage when I look.

2nd; transmission loss. I opted to have the inveter in the garage because the roof space used to suffer dramatic hot/cold swings. The PV panels now cover 90% of the space and has vastly reduced this problem. There is a 15m run of 6mm 12v supply. I have found calculators that suggest reducing this to 3m by moving the inverter will improve the situtation by c. 10%. That is around 1 kwh pd avg (44.8p pd inc export) and I can see a case for doing the move. There would be more power into the house as well.

thanks for any suggestions or references

The inverter will supply electricity at a higher voltage than the grid meaning it will be used in your property first with any surplus going to the grid.

You say your system is below grid voltage, how do you know what the grid voltage is? Note that the grid voltage is not always 240v.

The DC voltage from the panels will not be 12vDC. More like around 300-400vDC depending on how many panels in the string. Using 12v for the cable loss will give a wildly incorrect figure. I would leave the inverter where it is, I think the reduction in losses is not worth moving it.

grahamc2003

Jon_Tiffany wrote: »

You say your system is below grid voltage, how do you know what the grid voltage is? Note that the grid voltage is not always 240v.

.

...especially now the nominal voltage is 230v.