LPG or Solar Panels... Opinions Please!!

jacko74

Hi all

I'm looking to purchase a house in an area where there is no mains gas, the property currently has all electric heating... a water tank with immersion heater and night storage heaters, all very dated and in need of replacement.

I'm guessing my options are to remain ''all electric'' by upgrading the heaters and immersion and having solar panels fitted to power them or alternatively have bottled LPG central heating installed.

If I went down the solar panel route I could afford to buy them outright, but I don't even understand financially how it works when you own solar panels... do I still pay for electricity I use then get a payment back in the form of the feed in tariff? I have looked at various guides on solar panels (including the one on here) but unless I'm being a bit thick it doesn't really answer my question.. Basically, will solar panels mean I have no more electric bills?? Thanks in advance for any replies.

Robwiz

You're probably better off staying with Economy 7 and night storage heaters. If what's installed doesn't work then replacing with current models (Dimplex/Creda/etc) would be cheaper than installing lpg fuelled wet central heating. See Nottingham Energy Partnership for a comparison of prices. They show 6.82p per kWh for lpg whereas night rate electricity is around 5.4p on the most competitive tariffs. So lpg would cost more to run and the cost of installing a boiler, rads and all the plumbing would be far higher than replacing the storage heaters.

Solar panels generate electricity – the stronger the sun shines the more they generate. The inverter is connected to your supply and so you will use what you generate first before drawing from the grid. If you have surplus then that will flow to the grid. You have a generation meter in circuit which is used to pay your feed in tariff and usually it will be 'deemed' that you have exported half of what you generate.

Your panels will generate most during the daytime of the sunniest months – June, July and August. That's usually when usage is lowest so it's pretty difficult to use 50% of your generation in practice. Most people do things like run their dishwasher and washing machine when their generation is at its highest and maybe divert excess generation to an immersion heater. You pay for what you use from the grid (which should be less if you're making use of your own generation) and you get paid quarterly for your feed in units (which you have to advise your electricity company).

For daytime heat, it may be worth installing a split inverter heat pump in your living room – they achieve a coefficient of performance of 4 to 5 so work out as the cheapest cost per kWh of heat.

Smiley_Dan

Anecdotally, it's unlikely you'll find a way to use solar panels for space heating because (a) their output isn't enough, unless you've got a field of them and (b) even if they were enough, how would you heat the house during a gloomy run of days?

The best you can hope for is to use them for hot water using a diverter, and then only for about half the year.

In terms of total output, the output from a "standard" 4kWp array would be approx 3.6MWh, say. Compare that to the stated requirement for space heating on your EPC. I'm guessing it's a tad higher.

Even then, most of that production is in the summer, so you cannot use that energy when you need the heat.

Cardew

In short solar panels are nothing to do with heating the house. They will reduce your electricity bill and the savings could be between £50 and £150 a year. You will of course get the subsidies for your electricity generation. Provided you have a suitable roof, they are an investment in their own right.


If you decide not to go with Night Storage heating, why LPG - especially bottled LPG) and not oil CH?


I suggest you give storage heating a trial for a year before you make any important decisions.


As has been said many times, spend money on insulation to save money!


Also don't be taken in by the enthusiasm for heat pumps; in an older house the results can be disappointing.

jacko74

Thanks for the replies so far.

As I suspected it looks like it's a bit of a Hobsons choice for me with no ideal solution! Solar panels would give me the most electricity when I least need it (mid summer days) and conventional CH would need expensive bottled LPG.

I'd not really considered oil as I thought it was more expensive than LPG anyway? Plus this particular property only has a small and rather inaccessible back garden so I don't think an oil tank would go.

It is a good idea to live with the existing storage heaters for now so I can establish just how efficient or not they are.

Thanks again, anymore opinions welcome!

Robwiz

jacko74 wrote: »

I'd not really considered oil as I thought it was more expensive than LPG anyway? Plus this particular property only has a small and rather inaccessible back garden so I don't think an oil tank would go.

It is a good idea to live with the existing storage heaters for now so I can establish just how efficient or not they are.

Thanks again, anymore opinions welcome!

Go to the link I included in #2 which gives a comparison.

Night storage heaters, in fact all electric heating, is 100% efficient – all the energy is converted to heat output. If you do a forum search here on 'night storage heaters' you'll find lots of helpful tips on how to get the best from them.

captainhindsight_2

Your best options would be a heat pump or biomass boiler, and then maybe have solar pv or solar thermal to compliment the above.

Storage heaters / electric heating are so expensive to run!!

Silent_Dancer

Oil will be the cheapest off mains fuel to use in the majority of cases. LPG cost per kWh is about a third more expensive than oil for bulk supply and 50% more expensive in bottles and the boilers have similar efficiency.

Heat pumps theoretically can be cheap to run but are expensive to install and if badly installed or specified are expensive to run.

Another option are biomass boilers but these are expensive to install, require lots of room for a thermal store and fuel storage, are high maintenance with loading of wood and clearing ash, and are unreliable.

For both biomass and heat pumps the RHI subsidy can be claimed but you need the capital to spend upfront for the more expensive installation.

As others have said solar PV is not an option for heating but have you considered solar thermal for your hot water? Again RHI can be claimed.

Smiley_Dan

Last time I checked you were better off with PV for water heating, unless you have a really small roof space.

Ebe_Scrooge

Silent_Dancer wrote: »

Oil will be the cheapest off mains fuel to use in the majority of cases. LPG cost per kWh is about a third more expensive than oil for bulk supply and 50% more expensive in bottles and the boilers have similar efficiency.

Heat pumps theoretically can be cheap to run but are expensive to install and if badly installed or specified are expensive to run.

Another option are biomass boilers but these are expensive to install, require lots of room for a thermal store and fuel storage, are high maintenance with loading of wood and clearing ash, and are unreliable.

For both biomass and heat pumps the RHI subsidy can be claimed but you need the capital to spend upfront for the more expensive installation.

As others have said solar PV is not an option for heating but have you considered solar thermal for your hot water? Again RHI can be claimed.

This pretty much sums it up. Oil is far better than LPG, and is for *most* people the least expensive and simplest off-grid option. Biomass / pellets are an option, but are expensive to install initially and you need the space to store the fuel.

supermassive

All of these things for a living. I can get you a special MSE forum quote on it if you like :P

We're not "one of those" we're just a heating/electrics/plumbing company that's naturally progressed into green energy and things.

Anywho - your best option all around is to use solar for electricity, so you can run your electric heating at low or no cost, amongst other electric appliances. You would then be able to use a Solar IBoost in your hot water tank to transfer the spare electricity to your tank as and when. This is almost the same as having solar thermal, but instead of just the water heat, you get the electricity, too.

Feel free to PM me if you want any advice about biomass etc, as we're obliged to have ALL the details.

Just read the OP again.

Solar payback works like this:

You buy them. You get paid for each unit of energy you produce at a certain rate (around 14p) and also and added 4.77p to the 14p for exporting energy to the grid. If you're a domestic set up, it's not at all monitored and you can feel free to use the lot and still get paid for exporting.

These payments are locked in for 20 years at the rate on the start date of your solar set up. Meaning the longer you wait, the lower your payments will be locked in at. With them being guaranteed for 20 years, this in no way means you'll only get paid for 20 years. It's 20 years minimum. You will likely get the sign-up-date-rate for 20 years, and then move on to the end-of-20-years rate, whatever that might be... probably just the 4.77p for exporting by that point in time.

The average setup on a standard house (3 bed semi) is a 4kw system, 16 250w panels. The best on the market are Solarworld & Hyundai.

There are other details I could bore you with like the benefits of having microinverters if you're a high user, but I'm sure you can google it.

I would definitely advise you look into PV and an Iboost, though, as by the look of it, it solves all your problems.