Advice on renewables

teyhan1

Well-Known Member
I am about to move to a smallholding. With the move will come a little spare cash and I am considering some kind of renewable energy, PV, wind, Ground/Air source.
What are your experiences of any system you may have?
Any advice greatfully received.
I should say that I will be in Leominster, Herefordshire. Soil is heavy clay I believe. Land is flat at river level
 
The key to maximising the potential saving, and to fully utilise any of the renewable technologies you mentioned, is proper insulating of the building to begin with.
So consider updating the insulation, floor, walls and roof if you can, and sealing around all the openings.
No one systems can do the work of the other, ie you need to combine a mixture to get the best possible solution.

Air source & pv panels offer the best solution for most existing buildings.
No matter what the output from your panels, or what time of day it is, the most cost-effective strategy is to use all the electricity they produce.
If you install an air source heat pump to power your heating and hot water, you get the perfect partner for your PV panels excess output.

Roughly speaking for every kw you generate will be multiplied into 3-5 times as much heat energy, which can be automatically be fed into your hot water tank.
Ground source heating works best with modern houses, where there's a need for under floor heating, and naturally the insulation levels are already higher.

You should also look at the Renewable Heat Incentive RHI.
A Government backed scheme for grants for renewable technologies for domestic use.

Domestic Renewable Heat Incentive | Ofgem

Renewable Heat Incentive | Energy Saving Trust
 
I've heard that air source heating is not all that it's made out to be - the manufacturers make false claims about efficiency etc. My neighbour has just got rid of an expensive air source system and replaced it with an oil heating system.
 
Ground source is a costly way to get four heating unless you have plenty of photo voltaic solar panels,to run the pump etc .also the maintenance and disposal of the glycol in the pipe work. which must be replaced any time from 10 to 20 years. which is the life span of the fluid.then you also have the risk of ground freeze as well.
Better to go with wind or water powered electric for your energy. backed up with a wood burning stove/boiler if you can get enough wood cheap for next 20 years as every body is,putting wood boilers in.and the price of fuel is rising with the demand.

Bob
 
I've heard that air source heating is not all that it's made out to be - the manufacturers make false claims about efficiency etc. My neighbour has just got rid of an expensive air source system and replaced it with an oil heating system.

This, we spent ages looking in to both ASHP and GSHP. Nearly went for the latter but even though it was closer than air, we could never get the figures to stack up. Went with biomass in the end - wood is cheap.
 
Wind is not an option at all unless you have a average wind speed of at least 5mtrs/sec, there's a national wind speed database you can consult. The main problem with wind is that it only generates power when the wind speed is within a quite limited range as above a certain speed (around 20mtrs/sec depending on design) the tip speed is too high and cavitation occurs so the wind turbine has to be switched off. The main problem is that it may be generating when you don't need the power, e.g. the middle of the night, and you'll have to have a bank of batteries and a sophisticated control system to store the power for when you do need it. Vertical axis wind turbines are a better option than the standard horizontal axis versions (propellor type) as they don't have these narrow wind speed range problem, they start generating at lower speeds and don't really have a practical upper limit but in larger outputs, say 10mw plus, they generate such huge torque that the shaft often can't take the stress and they shear.

Air source heat pump power is cheaper than ground source but not as efficient in terms of generated energy coefficient and ground source is a pretty good option provided you have a suitable site for installation. Roof panels to heat water are also pretty good but both ground/air source and thermal roof panels only produce water to about 60oC and, whilst OK for hot water, this is not hot enough for central heating without a fossil fuel boost unless you have underfloor heating in which case it's fine. If not you are going to have to boost it by about 20oC to heat radiators. They won't work with a "combi" boiler system of course. PV solar roof panels are fine for direct electrical generation but without some sort of subsidy take an age to pay back, the are however getting better and payback times are shortening. You do not need a roof facing due south and they will generate in other than direct sunlight but you do have to be between SE and SW facing and on a pitched roof to get the best from them.

For hydro you obviously not only need a source of flowing water but one that has a minimum flow during the summer and your structure containing the screw will not have to be any impediment or danger to migratory fish moving up and down the stream. One option often overlooked but an extremely good form of renewable energy are anaerobic digesters but you need a constant source of organic material to feed it with and they are quite labour intensive, different feed materials produced wildly different outputs, for example cow muck is poor as a rule as the cows extract energy from their food quite efficiently but chicken muck is very good, a large chicken farm can often make more money from producing power from their effluent than selling chickens. Once you get to a large scale the methane output from an AD is usually burnt to generate power to be fed directly into the grid but this is not possible on a domestic scale and the methane generated becomes an alternative fuel for household burners such as cooker and central heating boilers.

If you have access to woodland or a supply of pellets then biomass is a good option but not everyone can get this.
 
Last edited:
The place I am buying has 3.4 acres so ground mounted PV is possible and therefore orientation to the sun not a problem.
From my understanding clay soil is not really suited to Ground Source.
I don't have underfloor heating as the building is part old barn and part 70's build.
Although near a river (more of a brook really) it is still 100m away, hence the £10,000 flood excess on the property.
So if I were to install PV and Air source how would you top up the heating, as it will go to rads and the air source won't generate enough heat to run them? Conventional boiler?
 
PV not on your Roof will need planing permission

PV is a good way to make some return as you get payed per unit unfortunately the Tories Cut the Price a while back We where lucky and got finished before so get 43p a unit index linked gives approx £1800 pay out by comparison the saving of using the electric ourselves only adds another £200 ish for the 4kw array and you can only use it when your in so Washing machines etc when the sun is up

Air source etc does work but you need a company that knows what they re doing i.e was around before the cowboys started up to get a fast buck and its as mentioned best to run underfloor as it operated at a lower temp than rads so ideal for AS /GS

you could look at a bio Fuel Burner you have the room to build a shed for it and a feed hopper etc
 
I've heard that air source heating is not all that it's made out to be - the manufacturers make false claims about efficiency etc.

welcome to the renewable sector!!

IMO many of the renewable or green energy alternatives are simply not efficient, cost effective or even green!!
half the issue with wind and solar energy is the massive toxic footprint created to build the bloody equipment
The only reason they become remotely of interest financially is the massive grants available to get them into production

Ground source more often than not requires electricity ...from..wait for it....coal fired generators!

if I had the choice of cheap, cost effective heating it would be a combination of systems designed to maintain an ambient temperature when not in use (high thermal capacity and flooring), as above effective insulation all round (often very expensive and difficult in old buildings) and a multi fuel waste burner (waste oil, waste wood, waste paper etc etc NOT pellets, they are expensive, fiercely overmachined for more impact)

trouble is if you want a hands off controllable system you need a fuel that can be regulated and delivered
 
I have been told that the equipment involved getting heat out of the ground is worn out before it has paid for itself.
 
One of the companies I do work for are a development company producing PV panel, only last week I was talking to their development manager,
His opinion on the current PV panel CR*P but will be good in 10years.
 
I've been looking into alll this stuff for a house i'm renovating.

There is a lot of cowboys at the renewable game so just watch who u get.

Try looking on the energy saving trust website, lot of info and they willl come out and tell u wot is vaible and wot isnae as well as a quite in depth report going into costings/savings etc. But depending on the house none might really be suited to u or cost so much not worthwhile. Like someone said earlier if u can insulate the house better thats the best way to go, possibly do a room at a time ripping plaster board down and backing with kingspan easy to do urself, but messy


Depending how remote u are but generally mains gas is the cheaper to run install than any renewables, if not got mains gas may be worth thinking about anything other than insulation.

Air source seem to be more common but i think it is just the ease of retro fitting them, the furthr north u get the less well they work.
Solar hot water panels work pretty well if roof faces the right direction and plumbing/heating system can take it.

Boimass esp if RHI/MCS accreddited costs a bloody fortune to install (been quoted 10-15k for a 2 bed house, and thats just the boiler and tanks, i expected to do all plumbing/heating for that) more and more folk are installing boimass, there will be a shortage of fuel in the future so prices will go up. Think on the commercail tarrif not a lot of profit between pellets and RHI payments now, bit more with logs or chip.
Unless u have access to wood u can log urslf probably not any better off on a boimass (and thats with ur time for free) with the oil prices the now a few farmers said they would be cheaper on oil the now

When u really look into them most are not really that finnacial vaible, and if they are its only the grants that make them vaible. Nt entirely sure most are that green either when u add up other costs
 
Before your big spend, ensure your building is totally draught proofed (actually check!) and well insulated (even insulate between each internal wall).
Next led lighting throughout your building - under 80 watts is easily achievable. The obvious idea is to make best use of your base facilities before investment.

Wood burners are the way forward, and being a shooter, there is a better chance of getting access to fallen trees from storms etc for cheap fuel .

Solar has its place, but get your energy usage in check with a meter to understand your daily requirements.
Wind turbines are great (and very popular where I stay), once you understand their best operating speeds, and combine with solar

To simplify, i would use wood burner, solar and wind turbine, and make your building as energy efficient as possible.
 
I'm setting up a new two bedroom apartment above my deer handling facilities now. It will be completely off the grid, large poly tanks for water, septic tank for sewer, bottled LPG gas for instant hot water, cooktop, large freezer when velveting & some back up lighting too, wood fire for winter heating, solar panels, 240 generator & a 2 stroke alternator for fast battery top up. It all needs to be simple to use for scientific types, not practical folk.

It will all be wired up in 240v back to inverters connected to 24v DC (batteries in series). The water pump from the rain tanks will be a 24v model straight to the batteries. A few seperate circuits from a couple of battery banks/inverters to lights & power in case one fails & also a power circuit just for "dirty" electricity if I really must use a geni, although I have inverter geni's I may want to hook up one with a dirty sine wave for some tasks.

The alternators can be salvaged from trucks & fitted to an old 2 stroke motor. These will recharge the batteries very fast in an emergency as they don't "trickle" a charge like a battery charger, they give the batteries what they want.

Sharkey
 
Last edited:
I looked after a friends log cabin a couple of years ago.
The main heating was the Air Source type made by Mitsubishi. It was struggling to maintain a reasonable ambient temperature, and totally overwhelmed if you wanted hot water for a shower.

I believe his electricity bill in winter is through the roof.

The property is a new build to the latest building regs. Well insulated and draught proofed.

He admits now that he wished he had installed a wood burner for the winter months.
 
Wood burners are the way forward, and being a shooter, there is a better chance of getting access to fallen trees from storms etc for cheap fuel .

If a landowner has taken the grants available(Stewardship?) all fallen timber has to be left to rot where it falls, for the good of nature!
 
Get a woodburner/s and plant a couple of acres of willow trees to supply the wood.

Combine this with a simple solar water heating system and you will avoid disappointment, I am sure the funds saved will allow you to indulge in smaller projects around the property concerned with heat retention & water treatment. If you are keen to produce food and meat then your money would be better spent in this area to assist with year round production & storage of your wares, chillers, dryers, quality smokers, good quality poly tunnel, log splitter, small tractor, trailers, digger etc, this way any future projects could be done quite easily yourself. That is where the satisfaction will be found.
 
Back
Top