Everything you need to know about installing solar panels on your farm


Soaring electricity bills and growing uncertainty about energy supplies have caused people across society to look for alternative ways to power their homes and businesses.

Solar technology is gaining popularity and the government is encouraging more people to supplement their energy needs with solar panels.

Farm families are, in many ways, best positioned 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 power:

Building permit

The installation of solar panels on or around dwellings or agricultural structures is considered an exempt development under certain conditions.

Ground-mounted solar — exemption conditions:

■ The field must not exceed 25 m2; and the height of the stand-alone solar panel should not exceed 2m.

Roof mounted exemption conditions:

■ Must not exceed 50 m2 or 50 pc of total roof area, whichever is lower; and, the solar panels must be at least 50 cm from the edge of the wall or roof on which they are mounted.

Buildings subject to conservation status and all major ground facilities require planning permission. If in doubt, it is advisable to contact the local planning officer before any expenditure.

VAT (flat-rate farmers)

A flat-rate farmer can reclaim the VAT incurred on the purchase of a solar photovoltaic system designed for use mainly or solely in his farming business.

The PV system must be named in the Triple E Product Registry – a list of products that meet the energy efficiency criteria of the Sustainable Energy Authority of Ireland (SEAI). See www.sai.ie.

The application is made via the Revenue Commissioners VAT Form 58.

Along with this VAT, farmers can deduct the full cost of their solar PV installation from tax in the first year under the Accelerated Capital Cost Allowance (ACA) scheme.

Photovoltaic solar installation

The angle and orientation of the solar generator are very important. As a rule, a photovoltaic installation requires a large roof or a space on the ground facing south.

The panels are either prefabricated encapsulated glass/plastic or in the form of tiles or semi-transparent PV glazing.

There are expensive systems that can track the sun over the course of a day throughout the year.

A traditional roof up to a 35° inclination angle is best for PV production. Avoid shading from trees, chimneys and other buildings.

TAMS support

If eligible, the Targeted Agricultural Modernization Program (TAMS) offers a 40% subsidy on a solar PV investment, while qualified young farmers can get up to 60% assistance.

PV installers must be on the SEAI registry or Department-approved list.

TAMS support is now available to support up to 11 kW of solar PV panels in dairy, cattle, tillage and sheep farms; Support of 40 pc was already available for the pig and poultry sector, and is not limited to 11 kW.

The horticulture sector can receive funding for solar photovoltaic and other energy-related projects through its investment assistance program.

Farmers should check their insurance to make sure they are covered for such work. They should insist on seeing the data sheets for the installed technology and getting written confirmation of the place of manufacture and warranties with exclusions.

Another key issue is the reputation and strength of the company, as some installation companies are financially close to the limit. Farmers must make installments to solid and sustainable companies.

Farmers need to ensure that purchased panels are warranted against ammonia erosion, especially on pig and poultry farms.

See the TAMS section of the Department’s website for full terms and conditions.


Solar panels on the roof of a shed

Solar panels on the roof of a shed

Network connections

The grid connection method so far is that for micro-generation installations up to 16 amperes (A) per phase (i.e. 3.68 kW single phase and 11.04 kW three phase), you do not need prior authorization to connect from ESB (ESBN) networks.

ESBN operates an “inform and adapt” policy, i.e. you complete the NC6 form (one page only) – email or post to ESB Networks and adapt after 20 days without any objections.

ESBN also operates a mini-generation pilot program for connections from 11 kW to 50 kW.

If your farm is suitable for a larger system, the process of connecting to the network is more complex.

If you have single-phase electricity, you can connect up to 17kW. If you have three-phase electricity, you can connect a generator up to 50kW.

But if your existing connection limit is lower than this amount, you will have 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 and help you through this process.

If you are not exporting, i.e. self-generating, you are using the CN6 form; if you are exporting, the CL5 must be submitted.

Contact ESBN at [email protected] or 1850 372 757.

Use of solar energy

Homes or businesses that use electricity during the day, ideally with a peak in the summer (for example, intensive ventilation of piggeries or poultry) are best suited for solar photovoltaic production.

About three quarters of the energy will be produced from April to September.

A large house with a south-facing unshaded roof of about 30 m2 could install 4 kW of photovoltaic panels.

Located, for example, in County Carlow and placed at the optimum angle to the sun (35°), it would generate approximately 3,300 kWh of electricity (roughly equivalent to the amount of electricity consumed by a small household) throughout the year.

A medium-sized array on the roof of a farm (50 kW) would require 250-300 m2 of roof space.

Installed on a southern slope, it could generate 41,500 kWh of electricity.

Alternatively, a 50 kW system could be ground mounted on metal frames, requiring about a third of an acre of land (0.1 ha).

The advantage is that this system can be oriented due south and tilted at 35° to obtain optimum performance.

The downside is that planning would be required, which adds extra time and cost to the project.

Energy Storage

Solar PV is generally not stored. However, farmers can store electricity as hot water by using power inverters to divert any excess energy from the solar system to their existing hot water tanks.

Dairy producers can then choose to do a hot wash in the evening rather than a hot wash in the morning after electricity at the night rate.

The main peak electricity demand on dairies concerns morning and evening milking; therefore, a storage battery and hot water supply inverter could 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, the batteries can be set to fully charge on the overnight electricity rate, for daytime use, for example during morning milking.

How your panels will reduce your bills and create revenue in the future

Once you have purchased your photovoltaic solar panels, maintenance and operating costs are low.

In general, solar panels require no maintenance because there are no moving parts.

The panels will require cleaning every year or two, but will mostly self-clean on a sloped roof with our typical rainfall patterns.

Inverters can also get dusty, which can lead to circuit failure. They will need to be replaced every 10 to 15 years and should be serviced annually as a preventive measure at low cost.

Panel production should be expected to fall at a rate of 1 pc per year.

The financial return is primarily related to the value and quantity of energy generated.

The payment you will receive for exported or spilled electricity may be the Clean Export Guarantee (CEG) or the Clean Export Premium (CEP).

The CEG is paid to you by your electricity supplier. Each electricity supplier now offers its own payment terms for energy exported to the grid.

It is important that farmers avoid being bound by a bad contract. It is easy for a utility provider to offer an attractive payment in kWh for excess electricity exported to the grid, only to offset any benefit and more with a high fixed price charged for the electricity purchased.

The CEG your supplier pays will tend to go up and down with the wholesale price of electricity.

The CEP provides for a payment of 13.5c/kWh fixed for 15 years. Based on the current high market prices, this is not competitive. However, it is fixed for 15 years, which gives certainty in relation to the world energy market.

The CEP tariff payment scheme was designed to optimize self-consumption of electricity rather than simply for export.

A farmer who uses more than 60 pc of ge It may be worth trying to get a 40pc TAMS grant for solar PV, even if it means not receiving export payments.

If, as in most cases, your solar photovoltaic panels operate in parallel with your mains power, they help to displace energy that you would otherwise have purchased from the grid.

For example, if your electricity requirement at any given time is 20 kW and your PV system was producing 5 kW, your net import from the grid would be 15 kW.

Each unit of electricity (kWh) you move from your imported needs effectively saves you on the imported price of that unit.

If you buy your energy at 35c per kWh and move 10,000 kWh, you save €3,500.

If you produce more energy than you use and your PV system is connected to the grid, the balance will be exported.

Barry Caslin is a Teagasc Energy and Rural Development Specialist based in Oak Park, Co Carlow


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