Solar Panels - energy price hikes making them more worthwhile?

QrizB

countryhouse39 said:

@QrizB i have no idea if the above is good or bad....!

The most important bit right now is this:

Yearly PV energy production [kWh]:881.59

So, for each kilowatt of south-facing colar panel you have installed, you can expect to generate 881 kWh of electricity. Imagine you installed a typical 4 kilowatt solar energy system, This would generate 4 x 881 = 3534 kWh per year, typically.

Then if you look at the bar chart you can see how the electricity is generated, month by month, through the year. You'll see that there's a lot more generated in the summer than in the winter.

If you know your typical energy use month-by-month (or if you have 12 months of bills or meter readings, so you can wortk it out) you can see for yourself how big a dent it might make in your bills. (If you had the 4kW system I mentioned above, each month you'd generate 4x the value on the bar chart.)

countryhouse39

@QrizB how do i adjust it to allow for a west facing roof?

QrizB

countryhouse39 said:

@QrizB how do i adjust it to allow for a west facing roof?

In the table next to the map, there are entries for "slope" and "azimuth". If you click on the words you'll get a pop-up explaining what they are measuring.

For due west, set "azimuth" to 90.

countryhouse39

@QrizB   so this is the graph for due west - i can see that it would be better to the south, but our south facing roof is more shaded (and to the street front). To my very inexpert eye this looks crap as hardly producing anything in Dec and January and that's when we have most of our usage (approx 2500kwh those months) but what do you think? thanks

Martyn1981

countryhouse39 said:

Coastalwatch said:

countryhouse39 said:

re-posting here for more views originally posted in 'energy' ...

We are lucky enough to live in an old house in the Scottish countryside (5bed, 3 reception) and as with many rural properties we aren't on the gas network. The people before us installed a GSHP for the heating and hot water, but they didn't install much in the way of insulation (out house is mostly pre 1900) so we have spent the last few years upgrading the insulation, and we installed some double glazing, but our electricity bills are still high as we use about 18-19000kwh a year...
With both of us WFH and 3 children I don't think we can reduce this much - so as you can imagine the recent massive hikes in energy prices are painful for us. We have been thinking of installing PV panels, maybe solar thermal too, but the possible savings didn't make it seem worth the outlay, however I am thinking that with the rise in energy prices that it will be worth it after all? Is anyone else in a similar situation? is it worth reconsidering so our bills go down? Can anyone advise on the best combination? we have roof space, sadly our south facing roof is also street facing and therefore unlikely to get planning permission for panels (conservation area) but we have a long west facing roof that is unobstructed. Any advise gratefully received

Hi CH, quite a conundrum you've pointed out there which I suspect will only be resolved by researching, obtaining quotes and asking questions on here and elsewhere. I concur with all those posting replies so far.

A west facing roof is good in the summer, as is an east, but in winter, when it's most needed the output would be very limited. Try inputting your location and other info into the link below to give an indication of likely output from any sized solar panel array through the year. If it's definitely a nogo on the south facing roof do you have anywhere you could erect solar panels to face south in the rear of the property?

https://www.google.com/search?client=firefox-b-d&q=pvgis+v5

I've no experience of Solar thermal but believe PV would be a more flexible form of energy as any excess can then be directed to areas other than hot water.

We've nearly 9MW of panels on the roof, which is approx our consumption annually. Unfortunately generation in winter is least when we most need it. It does also cover approx 75 % of our EV  transportation.

Hence we import around 4.5 MW annually.

To assist in offsetting the cost of imports we invested in Ripple Energy's wind farm, which is scheduled to commence generation in December. By doing this the wholesale cost of our energy will be fixed for the life of the windfarm, circa 25 years. Approx 2.5p/kWh, other fixed costs such as energy distribution etc which must also be accommodated in the cost of energy are not affected so no saving can be made on these.

While Ripples first windfarm is sold out they have announced a second, with slightly better returns, so may be worth investigating. Having invested in their first community owned windfarm I then invested further in the company itself.

Along with double glazing, thermal blinds can also be fitted to reduce heat loss and I've even backed these up with 50mm thick sheets of Celotex, cut to fit in the returns of the window spaces. Not used in summer or on mild winter days but popped in place from late afternoon during periods of sub zero temperatures in the darker days of winter.

I tried your link but dont have a clue how to use it! that's interesting about investing in a wind farm - i didn't know you could do this! can i ask how much you invested in the first place to then only have to pay 2.5p/kwh? 

Hiya, the idea behind the Ripple wind turbine is really great, with householders able to take direct responsibility for generating the equivalent of their consumption, or shortfall if they have PV.

Fully Charged just released a video looking at the Ripple idea and their next planned wind turbines:

Share a slice of the wind revolution - RIPPLE ENERGY | Subscribe to Fully Charged PLUS

countryhouse39

just to add more detail in to our usage  - rounded figures for what we used each month last year: (jan-december) kwh/month
2700
2300
2300
1600
1000
800
600
700
1000
1300
2100
2300

Martyn1981

Holy Cow CH! You need some PV mate. The good news, it would seem, is that you'll use most of what you generate even for a fairly large system, so the generation will mostly be worth whatever your leccy import cost is ...... assuming a lot of that consumption, especially Mch-Sept is on a day rate, not an E7 type tariff.

countryhouse39

Martyn1981 said:

Holy Cow CH! You need some PV mate. The good news, it would seem, is that you'll use most of what you generate even for a fairly large system, so the generation will mostly be worth whatever your leccy import cost is ...... assuming a lot of that consumption, especially Mch-Sept is on a day rate, not an E7 type tariff.

when you say Holy Cow does that mean we are using more than you'd expect for size/type house? I cant work out whether we are being really inefficient or not... 
We don't have E7 tariff - at the moment we just switched to Neon Reef's fixed tariff...i  am assuming they will probably go bust though and we will be screwed, hence my motivation to get our usage down/ generate our own!

QrizB

So the bad news is that 690kWh/yr from 1kWp of west-facing panels isn't great, but your energy consumption is high enough that you should be able to use quite a lot of it yourself instead of buying it from the grid.

I would suggest it's worth trying to get a system quote from someone and see what they can offer.

Martyn1981

countryhouse39 said:

Martyn1981 said:

Holy Cow CH! You need some PV mate. The good news, it would seem, is that you'll use most of what you generate even for a fairly large system, so the generation will mostly be worth whatever your leccy import cost is ...... assuming a lot of that consumption, especially Mch-Sept is on a day rate, not an E7 type tariff.

when you say Holy Cow does that mean we are using more than you'd expect for size/type house? I cant work out whether we are being really inefficient or not... 
We don't have E7 tariff - at the moment we just switched to Neon Reef's fixed tariff...i  am assuming they will probably go bust though and we will be screwed, hence my motivation to get our usage down/ generate our own!

Hiya, sorry I shouldn't be teasing you. As you say, for location and property size, it's not so bad, and hopefully you can still do some bits and bobs to improve insulation.

My thoughts were more around the PV issue, since even in the summer, you'd probably be able to make use of most of the generation. Looking at the 600-800kWh months, I'll assume most of the consumption is during the day, or can be moved to the day, so you'd hopefully be able to make use of 400kWh's+ of PV generation, so not too much exported. For the rest of the months, you'd probably be able to consume almost all of the generation. So at least you can value most of the generation at leccy import prices, which will help the economics of PV massively.

Certainly worth seeing if a ground mount is possible, since you would benefit from a steeper pitch south facing, to boost winter generation. If you play with PVGIS and see how going steeper reduces summer gen, but boosts winter gen.

Just playing, but I stuck a pin in Perth and for 35d pitch west facing I get 675kWh/kWp pa, and Dec gen of 5.72kWh, but for 50d pitch south facing I get 846kWh/kWp pa, and Dec gen of 19.26kWh,