Everything you need to know about installing solar panels on your farm
Barry Caslin, Teagasc Energy & Rural Development Specialist, answers all your questions about solar panels: where do you put them, what type do your get, can you get a grant, are they tax-deductible, do you need planning permission, how do you export to the grid?
Soaring electricity bills and rising uncertainty over energy supplies have left people right across society seeking alternative ways to power their homes and business.
Solar technology is growing in popularity, and the Government is encouraging more people to supplement their energy needs with solar panels.
Farm families are, in many ways, best placed to take advantage of this trend due to their access to space and often high energy costs.
Here we look at some of the key factors farmers should consider before investing in solar:
The installation of solar panels on houses or agricultural structures, or within their curtilage, is considered exempted development subject to certain conditions.
Ground-mounted solar — exemption conditions:
- The array shall not exceed 25m2; and the height of the free-standing solar array shall not exceed 2m.
Roof-mounted — exemption conditions:
- Shall not exceed 50m2 or 50pc of the total roof area, whichever is the lesser; and, the solar panels shall be a minimum of 50cm from the edge of the wall or roof on which they are mounted.
Buildings subject to conservation status and all larger ground-mounted installations require planning permission. If there is any doubt it is advisable to contact the local planning officer before any expense is incurred.
VAT (flat-rate farmers)
A flat-rate farmer can claim back the VAT incurred on the purchase of a solar PV system that is designed to be used mainly or solely in his or her farming business.
The PV system must be named on the Triple E Product Register — a list of products which comply with the Sustainable Energy Authority of Ireland's (SEAI)energy efficiency criteria. See www.seai.ie.
The claim is made through the Revenue Commissioners VAT 58 form.
Alongside this VAT, farmers can write the entire cost of their solar PV installation off against tax in year one under the accelerated capital allowance (ACA) scheme.
Solar pv siting
The angle and orientation of the solar array is very important. Generally a photovoltaic installation requires a large south-facing roof or field space.
Panels are either pre-constructed encapsulated glass/plastic or may take the form of roof tiles or semi-transparent PV glazing units.
There are costly systems that can track the sun over the course of a day throughout the year.
A traditional roof up to a pitch angle of 35° is best for PV output. Avoid shading from trees, chimneys and other buildings.
If eligible, the Targeted Agricultural Modernisation Scheme (TAMS) provides a 40pc grant on a solar PV investment, while young qualified farmers can get up to 60pc in grant aid.
PV installers need to be on the SEAI register or the Department-approved list.
TAMS support is now available to support up to 11kW solar PV on dairy, beef, tillage and sheep farms; 40pc support was already available to the pig and poultry sector, and is not limited to 11kW.
The horticulture sector can receive funding for solar PV and other energy related projects through its Scheme of Investment Aid.
Farmers should check their insurance to ensure that they have cover for such work. They should insist on seeing datasheets of the technology being installed, and get written confirmation of place of manufacture and warranties with exclusions.
Another key issue is business reputation and robustness, as some installer companies sail close to the edge financially. Farmers need to pay deposits to companies which are solid and going to be around for the long term.
Farmers need assurances that purchased panels are warranted against ammonia erosion, especially on pig and poultry units.
See the TAMS section of the Department website for full terms and conditions.
The grid connection method up until now is that for micro-generation installations up to 16 amps (A) per phase (that's 3.68kW single phase and 11.04kW three phase), you need no prior permission to connect from ESB Networks (ESBN).
ESBN operate an "inform and fit” policy, ie, you fill in form NC6 (single page) — email or post to ESB Networks and fit after 20 days of having not received any objection.
ESBN also operate a Mini-Generation Pilot Scheme for connections from 11kW to 50kW.
If your farm suits a larger system, then the grid connection process is more complex.
If you have single-phase electricity, you can connect up to 17kW. If you have 3-phase electricity, you can connect a generator up to 50kW.
But if your existing connection limit is below this amount, you will need to pay ESBN for an increase. It's a good idea to get your electricity bills and discuss them with an electrician at the start of your project.
Your Solar PV installer should also be able to advise you and help you through this process.
If you do not export, ie, auto-generator, you use the NC6 form; if you do export then it is the NC5 which must be submitted.
Contact ESBN at firstname.lastname@example.org or 1850 372 757.
Using solar energy
Houses or businesses that use electricity during the day time, ideally peaking in the summer (eg, ventilation of intensive pig or poultry livestock sheds) are best suited to solar PV output.
Around three-quarters of the energy will be produced from April to September.
A large house with an unshaded south-facing roof of around 30m2 could install 4kW of PV panels.
Located in, say, Co Carlow and set at the optimum angle to the sun (35°), it would generate around 3,300kWh of electricity (roughly equivalent to the amount of electricity consumed by a small household) throughout the year.
A medium-sized array on a farm roof-top (50kW) would require 250-300m2 of roof space.
Installed on a south-facing slope, this could generate 41,500kWh of electricity.
Alternatively, a 50kW system could be ground-mounted on metal frames, requiring around a third of an acre of land (0.1ha).
The advantage is that this system could be aligned due south and angled at 35° to obtain optimal performance. The disadvantage is that planning would be required, which adds further time and cost to the project.
Solar PV is generally not stored. However, farmers can store electricity in the form of hot water by using power diverters to divert any excess power from the solar system into their existing hot water cylinders.
Dairy farmers may then opt to do a hot-wash in the evening as opposed to a morning hot-wash after night-rate electricity.
The main peak demand for electricity on dairy farms is for the morning and evening milking; hence, a battery storage and hot water power diverter might be a sensible solution.
Pig and poultry units have a continuous demand profile with a constant demand for electricity, so battery storage is not required.
In some cases, batteries can be set to charge to full on the night rate electricity, for daytime usage, say in morning milking.
How your panels will cut your bills — and create income in the future
Once you have bought your solar PV panels, the maintenance and operating costs are small, writes Barry Caslin. In general, solar panels will require no maintenance as there are no moving parts.
The panels will require cleaning every year or two but will mainly be self-cleaning on a pitched roof with our typical rainfall patterns.
Inverters can also get dusty, which can lead to circuit failure. They will have to be replaced every 10 to 15 years and should be serviced annually as a low-cost preventive measure.
Panel output should be expected to fall at a rate of 1pc per year.
The financial return is mainly tied up with the value and amount of energy generated.
The payment you will receive for exported, or spilled, electricity, can be the Clean Export Guarantee (CEG) or Clean Export Premium (CEP).
The CEG is paid to you by your electricity supplier. Each electricity supplier is now offering its own payment terms for energy exported to the grid.
It is important for farmers to guard against getting tied into a bad contract. It is easy for a utility provider to offer an attractive kWh payment for surplus electricity exported to the grid, only to offset any benefit and more with a high fixed-term price charged for bought-in electricity.
The CEG that your supplier pays will tend to go up and down with the wholesale price of electricity.
The CEP provides a payment of 13.5c/kWh fixed for 15 years. Based on current high market prices, this is uncompetitive. However, it is fixed for 15 years, which gives some certainty by comparison to the global energy market.
The CEP tariff payment scheme was designed to optimise self-consumption of electricity rather than simply for exporting.
A farmer who uses over 60pc of generated electricity may be better off trying to secure a 40pc TAMS grant for solar PV, even if this means not getting the export payments.
If, as in most cases, your solar PV panels operate in parallel with your mains supply, they help to displace the energy you would otherwise have bought from the grid.
For example, if your electricity need at a particular time is 20kW and your PV system was producing 5kW, your net import from the grid would be 15kW.
Each unit of electricity (kWh) you displace from your imported requirement effectively saves you on the imported price of that unit.
If you buy your energy at 35c per kWh and you displace 10,000 kWh, you save €3,500.
If you are generating more energy than you are using and your PV system is connected to the grid, the balance will be exported.
This article was first published in the Irish Independent