The power to choose

Whether it's wind, hydro-electric, or biomass, sustainable energy sources must move centre stage

Bruce Lett

With the current downturn in rural incomes, and the economy in general, many farmers are looking at alternative methods of generating income and reducing farm costs.

For many, wind power is an attractive option as most wind turbine structures have a small footprint and fall within the financial capabilities of many farmers.

Professor Michael McElroy, from the Environmental Sciences department at Harvard University in the USA, once said in a response to a question about the potential of nuclear power in Ireland: "Ireland is potentially the Saudi Arabia of wind energy and could export electricity all over Europe."

Other alternatives such as water turbines, biomass, and rapeseed methyl ester (RME) are gaining momentum as oil prices creep up and technology matures.

Here we examine some of these options in an attempt to assess the potential of these technologies in an agricultural environment.

  • WIND: Generating electricity by wind has, by far, provided the most interest among the farming community. At this year's Ploughing Championships, there were quite a few turbines on show and there appeared to be a substantial amount of genuine interest in them and their potential. Wind generation can be divided into two main areas: micro generation and commercial generation.

Micro generation is the area that will be of most interest as a source of income or for offsetting electricity bills. Firstly, they tend to be relatively small, which makes installation fairly straight forward, with little more than a telescopic loader required to put it in place. Things are further simplified if the unit is no higher than 20m to the tip of the blade in the vertical position as there is no planning permission required -- though it would be advisable to check with your local county council planning authority first.

There is an enormous variety of products out there with a wide range of generating capacities. Turbines with a capacity of about 5kWs or 6kWs seem to be the recommended norm for a four- to six-bedroom house, with the potential to sell the excess electricity back to the grid. A turbine with the export capacity to the grid of 6kW is the maximum the ESB allows if you are connected to a single-phase supply. If you are connected to a three-phase supply, the maximum export capacity increases to 11kW.

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There is a huge number of generation configurations available as well. Galway company NGS Energy displays several of these on its website, There you will see a variety of combinations with or without grid connections (and PV/solar panels) for everything from connecting to your immersion heater in the hot water cylinder to remote water pumping. Another Galway company, C&F Wind Energy (www.cfwind states that its turbines are completely designed and manufactured in Ireland. Part of the C&F Engineering Group, C&F Wind Energy, manufactures a range of turbines from 6kW to 15kW.

An interesting entrant to the wind turbine market seen at the Ploughing Championships was Moffett Engineering's Robert Moffett (, creator of many unusual products such as the Moffett Mounty, Combi Lift, MFT tractor, and more. Mr Moffett said he had a micro generator for a few years before he decided to develop his own wind turbines.

"This was further aided by the relaxation of the planning laws and the ESB came forward with its connection facility," he said.

Mr Moffett said his 10kW turbine costs €17,000 + VAT -- and that is just for supply. He said many farmers prefer to do the base themselves (to Moffett specifications).

"We just supply the anchor bolts. Moffetts can do the electric installation work or the customer can get that done themselves," he said.

All arrangements seemed quite flexible but Mr Moffett said they all had to meet the required specifications, particularly for the electrical installation.

At the high capacity end of the micro market, into commercial territory, is a wind turbine imported by Wicklow company RES (Renewable Energy Systems) Ltd ( The Canadian-built MaManna AOC15/50 is a 50kW wind turbine, which RES says has been designed for agricultural, institutional, commercial and industrial applications.

RES's Brendan Foley says: "Target markets for this turbine would be the likes of poultry and mushroom farms, industrial users, stud farms and even golf clubs."

Mr Foley said all aim to cut their energy costs but suitability would depend on the site.

"On a good site, a typical pay back would be from around eight to 12 years. While this does seem a long time, it isn't bad, considering it has a life span of about 30 years."

Both RES and NGS Energy have teamed up with Bank of Ireland to bring green business loan customers a range of incentives from free site visits to extended warranty or discounts on some products -- depending on the company. Mr Foley pointed out that it seemed to be an area that banks were willing to give loans to.

Certainly worth mentioning is that ESB Networks will provide import/export metering free of charge to the first 4,000 domestic customers installing a micro generator (within a three-year period). ESB will also provide a support payment of 10c/kW/hr for the first 3,000kW/hr exported annually to the same customers. This rate is in addition to the rate offered by the customer's electricity supplier. To take part you would need to notify ESB Networks using the micro generation form (NC6), which is available to download from loads/form_nc6.pdf.

With the current economic climate and at current electricity prices and product prices, there appears to be a consensus that it will take 10-15 years before the unit pays for itself and there is a return on your investment. The most variable aspect of this is, of course, the wind factor -- the better your site's access to the prevailing winds and unobstructed windflow the better. Every supplier will have the facility to provide a site and wind assessment for you. Obviously, the longer the wind-test period the better the data.

Commercial generation might just be an alternative for individuals with both a site and initial capital required for the investment. This is not for the faint hearted, though, as the monetary investment required is quite large and the processes involved, such as planning permission and grid connection, are often lengthy and frustrating.

To give a brief outline of what is required, I attended an information evening in Wicklow about a joint windfarm development between Coillte and the ESB. They propose to construct a wind farm at Raheenleagh, Croghan, Co Wicklow -- close to the Wexford border -- that consists of 11 wind turbines capable of producing 27,500kW of renewable energy.

Each turbine will be about 70m tall, its blades will be 45m long and each one will cost well in excess of €1m -- that gives you the scale of such a development.

Paulo Amante of Coillte outlined the process from start to finish -- in terms I could understand!

"Firstly, there are early energy assessments based on a preliminary layout determined by site size and quality," he said.

"After that the preliminary environmental impact statement (EIS) looks at wildlife in the proposed area, maps of National Habitat Areas and special protection areas.

"Around the same time an electrical connection is sought with either Eirgrid (transmission) or ESB Networks (distribution) depending on requirements. Following on from that, roads, layout and basic constructability is looked at."

The next major stage Mr Amante outlined is to go for full EIS.

"As part of that, there is a public consultation and stake holder consultation, ie fisheries, National Parks and Wildlife, etc. It is only after all of this that planning is submitted. If all is successful, then construction can begin."

As you can see from Mr Amante's brief outline, there is potentially an enormous amount of work, difficulty and cost involved. Also, the grid connection has to be paid for as well. All can, and does, take years, but the financial rewards are reputed to be substantial, with projects often paying for themselves within a decade.

  • Hydro electricity -- Hydro electric generation -- even on a small scale -- can be a more cost-effective and, more importantly, predictable and consistent method of generating electricity on both a micro and commercial scale. If you are lucky enough to have a decent size stream running through your farm, it may certainly be worth looking at.

Co Wexford-based Eco Evolution ( is the agent in Ireland for the Rehart range of Archimedean Screw hydro turbines supplied by Mann Power Consulting Ltd, the Archimedean Screw hydro turbine specialists in the UK, although manufactured in Germany. Mann Power is the sole authorised dealer for the Rehart range of Archimedean Screw Hydro turbines.

Frank Gethings is the MD of the Ferns-based company, which specialises in the micro-generation technologies of wind turbines, Rehart hydro turbines and solar PV systems. It also supplies and installs solar thermal systems, air-to-water heat pumps and mechanical ventilation with heat recovery (MVHR) systems.

The Archimedean Screw is old technology used as water pumps to lift water from one level to another. Rehart manufactures two types of the Archimedean Screw, one for pumping water -- as originally designed -- and the other to generate electricity using the flow of water in the reverse direction, downwards to turn the screw and generate power.

Mr Gethings says: "The requirements for driving the screw are quite low, with a minimum head requirement of just 1m, up to a maximum of 10m. There is a minimum flow requirement of 100 litres/sec, which is the equivalent of a sizeable stream."

These are said to have many advantages over the more traditional types of hydro turbines; the most important of these probably being the fact that they are fish friendly. Also, leaves and debris simply pass through the turbine with no fine screening required.

"They are also highly efficient across a large flow variation, with a hydraulic efficiency of 87pc and a water-to-wire efficiency of 77pc. They are suitable for small, domestic applications from 1kW up to larger commercial applications of 350kW.

"With each application we would have to do a feasibility study on each site and then the Archimedean hydro-electric plant would be custom-made to suit the site." Small plants would generate as little as 1kW, while bigger plants could generate up to 350kW handling a water flow of up to 10,000 litres/sec.

"Old mills are ideal sites as the civil works are already in place and there is the potential to generate up to 15kW or so, depending on what's there."

Planning permission would be required for such an installation, and in the UK they have gone through all the processes to establish it as a fish-friendly design. Being site specific, it could be hard to estimate the price of installing such a facility, but MannPower Consulting has produced a chart in an effort to do just that.

Irish Independent

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