how do solar systems work

theoldwaster

hi

saving money is an entirely new concept to me but a rapidly approaching retirement and corresponding drop in income has forced me into looking for reducing household expenditure.


one thing i have done is to sign up for a solar panel deal whereby a company installs panels on my roof where i supposedly recieve the electricity produced and they recieve a payment through government subsidy for each unit produced.

i'm presuming all the electricity i use will still appear on my household meter so how will my supplier know how much was drawn from the grid and how much was produced from my own roof.

thank you to anyone who can enlighten me

Cardew

Welcome to the forum.

The companies(known as Rent-A Roof) get money for every unit(kWh) of electricity you generate from the solar PV panels on your roof.

It doesn't matter to them if you use all that electricity or none, they still get their money.

So you can use as much as you can manage, however it is not easy to use a lot - especially if your water is heated by gas. Typical savings vary between £50 and £150 a year.

However you have to sign a 'lease' to allow them to use your roof for 25 years. There is plenty of evidence that it will be difficult to re-mortgage or if you sell the buyer to get a mortgage.

All in all IMO it is a dreadful deal with the company getting most of the money. You would be far better off paying for the PV panels and getting all of the money.

A lot more about this subject in the 'Green' section of MSE.

rogerblack

theoldwaster wrote: »

saving money is an entirely new concept to me but a rapidly approaching retirement and corresponding drop in income has forced me into looking for reducing household expenditure.

To not directly answer the initial question.
START NOW.
Go over to the 'debt free' side of the board, and the MSE budgeting tool - https://budgetbrain.moneysavingexpert.com/auth/login .

Start cutting all your expenses now.
Slightly more on-topic for the gas/electricity board - I would recommend getting two meters.
One a plug-top meter that you plug into the socket, plug the appliance into, and leave it for a day (if it's an intermittently run appliance) to see how much power you're using.
Like this one from ebay.

And a whole-house meter to tell you what you're using at any given moment.
Similar to this

Some energy providers were giving these away free or at a reduced price - check.

Some energy saving measures pay back really quickly.
Replacing a 100W bulb used 8h/day - 2 months.
Draughtproofing windows - days or weeks.
Turning your heating down 1C - instant.
Using an electric blanket or throws rather than having the heating on - days/weeks.
Buying a thicker jumper, slippers, or wearing more layers - weeks.
An old fridge on its last legs - a couple of years.
It's rare that any energy savings are easy or massive.

(Though do make sure you've switched supplier to the best deal for you.)

WestonDave

To answer the question you asked to complement the useful information you've already had, the feed from your solar panels will supply your consumer unit/fuseboard before any electricity comes in from outside. So if your panels are generating and you turn your washing machine on, the household electric will use the solar generated electricity with any surplus going out to the national grid. Your electricity meter shouldn't record anything at this point as it shouldn't record outgoing electricity and so will only clock up if you are using more than you are generating. (There are some old clock style meters that run backwards which you will need to get your energy co to change for a modern one that doesn't). Obviously at night when you stick the kettle on all the electricity will come from outside and your meter will clock up the usage.

There are devices coming on the market which will detect whether you have surplus solar power and if so turn on say an immersion heater or in some case a plug adapter to enable a small heater to be run - this maximises the free energy use but of course you will have to pay for the device (which varies from around £150 to much more).

theoldwaster

WestonDave wrote: »

There are devices coming on the market which will detect whether you have surplus solar power and if so turn on say an immersion heater or in some case a plug adapter to enable a small heater to be run - this maximises the free energy use but of course you will have to pay for the device (which varies from around £150 to much more).

HI thanks for all the replies which have answered the question but the device above sounds interesting is there any more information you have on such devices such as where to purchase, what they are called ect.

WestonDave

There are a variety of them - the immersun is an immersion heater controller which I think is fairly expensive, and needs installing by an electrician, but probably offers the best savings especially on a free system. Another brand name one is the "optiplug" which is potentially self install and allows a particular plug socket to effectively be controlled so that it switches on when there is surplus power. There is a whole thread on "intelligent switches" on the Green and Ethical part of the forum - if you either use the drop down menu top right or go back to the main menu and scroll down you'll find it. Its where most of us solar fanatics hang out most of the time so you'll get a lot more detailed advice there!

theoldwaster

WestonDave wrote: »

There are a variety of them - the immersun is an immersion heater controller which I think is fairly expensive, and needs installing by an electrician, but probably offers the best savings especially on a free system. Another brand name one is the "optiplug" which is potentially self install and allows a particular plug socket to effectively be controlled so that it switches on when there is surplus power. There is a whole thread on "intelligent switches" on the Green and Ethical part of the forum - if you either use the drop down menu top right or go back to the main menu and scroll down you'll find it. Its where most of us solar fanatics hang out most of the time so you'll get a lot more detailed advice there!

Thanks again for all your help. i looked at both the devices you named. we dont have an immersion heater we have a gas combi boiler so the optiplug looks the best option for me.