A call for submissions on Ireland's Draft Renewable Electricity Policy closed at the end of April. Féidhlim Harty advises diversity, rather than an over-reliance on large scale wind as the only option of choice

If decarbonisation is to be adopted in a manner that will meet the targets set out in the Paris Accord last year, burning of all fossil energy sources, including indigenous peat, will need to be eliminated completely as sources of electricity. To meet the shortfall created by a decarbonisation of power generation, we will need to explore every available generation option, not just large-scale wind power.

There are many options available that need to be researched and funded on both small and municipal scales. Many more are well proven, but need to have policy obstacles removed in order to be able to flourish. The more these generation options can double up on useful outcomes the better, saving fuel elsewhere and/or sequestering carbon, rather than simply minimising carbon generation.

Examples of different energy options

• Bioenergy from willows grown on sewage-treatment plant discharges can be used to mop up nitrates and phosphates. These nutrients currently cause serious water quality deterioration in Ireland, but can instead provide a fertiliser source for willow plantations. This approach has already been used by Monaghan County Council in one example of municipal sewage treatment, and in a growing number of single-house systems around the country.

• Current forestry policy prevents the use of woodland buffer-zones for protection of water courses because forestry is deemed to be net polluting rather than net beneficial. Although this is the case for widespread conifer plantations, it need not apply to careful planting and harvesting practice, and careful selection of tree species. We could create a much healthier aquatic environment in Ireland and clean up our rivers, lakes and streams by careful planting of deciduous trees in wooded riparian zones along all rivers and streams. The timber grown could form part of our biomass fuel stock to replace peat and oil fired stations.

• Biochar combined heat and power (CHP) boilers can generate both district heating and electricity, while at the same time creating biochar (1) as a valuable ingredient in fodder mixes for livestock and as a soil improver. This has the potential to lower greenhouse gas emissions from cattle directly and create healthier, carbon-rich soils, which in turn helps to address flooding issues seen in recent years. The biochar itself is a very stable form of carbon for atmospheric carbon sequestration and can be actively beneficial for farm animal and soil health.

• Sewage treatment plant sludges can be sources of biogas via anaerobic digestion, as well as producing a nutrient-rich digestate for agricultural use and therefore displacing high energy input fertilisers (2).

• Septic tank sludges would overload current municipal capacity if the National Inspection Plan were to be followed to the letter and tanks were to be maintained annually as recommended. Instead of this situation, collection of sludges for anaerobic digestion would stabilise the digestate and also prevent the overload of current municipal sludge treatment facilities.

• Domestic scale zero discharge willow facilities offer a dual benefit in that they mop up atmospheric carbon as they grow, using the nutrients from the septic tank, and can be used to offset heating fuel requirements in the house from the timber generated after routine coppicing maintenance. Recent EPA Research Report findings (3,4), suggest that these are excellent at protecting the local watercourses, and research from Denmark suggests that each willow facility will mop up as much carbon over 20 years as a mechanical treatment system will generate in that timeframe if the fuel wood is used to displace heating oil or electricity in the home.

Diversifying energy sources

Small, diverse energy-generation sources have the potential to produce the majority of Ireland’s electricity needs into the long term. The lower limit of 50MW proposed in the Electricity Policy is inappropriate in this regard in that it runs the risk of greatly hampering the widespread uptake of domestic and community scale generating technologies.

There is no mention in the document of micro-hydro, for example, which is a valuable source of rural power generation for appropriate sites; nor roof-top solar, or domestic scale renewables of any sort. This is a serious oversight in energy policy going forward. By diversifying our energy sources, and providing a guaranteed return to small scale suppliers throughout the country we could free up a groundswell of renewable energy sources as homeowners explore ways to make use of local resources.

Ireland has an abundance of infrastructure already in place for hydro electricity generation. Most towns and many villages in Ireland have old mill races in place. In recent decades, many of these have already been restored to a limited extent for aesthetic and heritage reasons. These mill races have the potential to be easily converted to municipal-scale hydro generators.

One of the largest sources of carbon emissions in Ireland is transport. There are already incentives for electric vehicles in Ireland, but these need to be increased in order to dramatically increase decarbonisation in this area. If every house with a vehicle were to be fitted with a rooftop solar array of PV cells to power that vehicle, ongoing carbon emissions from transport would become almost negligible overnight. This does not address embedded energy caused by transport infrastructure and the wider transport industry, but it would be a good starting point at least.

Hand in hand with power generation, we need to consider where our power is used. Many technologies used in day-to-day life are actually unnecessary. Sewage treatment, for example, can be achieved with gravity-fed technologies such as reed beds, constructed wetlands and zero discharge willow facilities rather than with conventional electric powered mechanical treatment systems.

There is currently no bias in planning or Environmental Protection Agency guidance to promote zero energy, or net carbon negative technologies, and this is an important change that needs to be adopted across all sectors – not just for wastewater treatment.

One of the principal challenges for reducing greenhouse gas production, and instead for sequestering atmospheric carbon in Ireland, is the prioritisation of economy over environment. Nonetheless, despite the lack of funding for renewables, fossil energy generation is subsidised (5). On this note, the chief economist of the International Energy Agency has said that eliminating global subsidies for coal, oil and gas could provide half of all carbon reductions needed to prevent catastrophic climate change (6).

If we are to achieve the COP 21 Paris goals, subsidies to fossil energy companies and high energy consumption industries in Ireland will need to be identified and cut, with financial resources focused instead on the identification and support of renewable energy generation and zero energy use technologies.

Cap and Share

In order to make all of the above practical from a financial perspective, Feasta’s Cap and Share (7) (or UK Tradable Energy Quotas (8) etc) proposals should be adopted by government as a matter of urgency, and promoted by our representatives at European and UN levels. Under Cap and Share, fossil fuels are viewed as a global commons, which everybody should benefit from – but which also need to be capped at safe production limits.

Cap and Share proposes to set a limit on annual carbon emissions. Permits are issued accordingly for fossil fuel extraction. These are then bought at auction by energy companies and the money raised is shared equally to everyone on the planet (easier than ever before with online and mobile cash transfer infrastructure). This inherently rewards low-energy users, whether individuals or whole nations, and also encourages greater saving of energy through direct financial incentives.

In this way, Cap and Share offers a clear and open way to show which products, services and industries have high energy demands, because the cost of the embedded energy is passed on to the final buyer rather than hidden behind subsidies and shared distribution of losses to tax-payers. We have seen such losses in Ireland recently in terms of flooding and storm damage, and have yet to see fossil energy companies jumping in to pay their share of the damage done.

Engineering is fundamentally a discipline of finding and implementing solutions. There are many technologies currently available that can help us meet the challenge of the COP 21 Paris Accord to keep global temperature increases below 1.5 to 2°C, and many more are surely yet to be developed. What is needed is to adopt these at every scale and level, and to diversify the energy sector as much as possible.

Perhaps the open-source revolution that has occurred online can have similar results in our energy sector if we promote a diverse and community-involved attitude to finding and adopting the solutions we need.


(1) EOS Future Design, Ithaka Institute, Tipperary Energy Agency, University of Limerick and Premier Green Energy (2015) PBX2 – Pyrolysis of Biomass for Power and Biochar. Report by EOS Future Design, Dublin, funded under the SEAI Energy Research, Development and Demonstration Programme.
(2) Harty F (2016) Closed Loop Agriculture for Environmental Enhancement: Returning Biomass and Nutrients from Humanure and Urine to Agriculture. Biodiversity Work Package 2015. Feasta, Dublin. (In Press. Draft document available at http://www.feasta.org/2016/01/12/draft-report-promoting-closed-loop-agricultural-practices-for-biodiversity-enhancement/)
(3) Gill LW., D Dubber, V O’Flaherty, M Keegan, K Kilroy, S Curneen, B Misstear, P Johnston, F Pilla, T McCarthy, N Qazi and D Smyth (2015) ‘EPA Research Report – Assessment of disposal options for treated wastewater from single houses in low-permeability subsoils’. EPA, Wexford.
(4) Harty F (2016) Willow facility update: EPA research options for low-percolation sites. Engineers Journal online. https://www.engineersjournal.ie/2016/02/23/epa-research-report-on-solutions-for-low-permeability-subsoils/
(5) Douthwaite R and D Healy. Subsidies and Emissions of Greenhouse Gasses from Fossil Fuels. A report to Comhar the National Sustainable Development Partnership on behalf of Feasta, the Foundation for the Economics of Sustainability and Friends of the Irish Environment. Comhar, Dublin.
(6) Clarke D (2012) Phasing out fossil fuel subsidies “could provide half of global carbon target”. The Guardian, UK. http://www.theguardian.com/environment/2012/jan/19/fossil-fuel-subsidies-carbon-target
(7) Cap and Share website details http://www.capandshare.org/
(8) Tradable Energy Quotas website details http://www.teqs.net/

Author: Féidhlim Harty, FH Wetland Systems Ltd, 30 Woodlawn, Lahinch Road, Ennis, Co Clare. Email: reeds@wetlandsystems.ie. See: www.wetlandsystems.ie. Harty is the author of ‘Septic Tank Options and Alternatives – Your Guide to Conventional, Natural and Eco-friendly Methods and Technologies’. In bookshops and online now. See www.wetlandsystems.ie/shop.html  

http://www.engineersjournal.ie/wp-content/uploads/2016/06/Renewable-energy-1024x780.jpghttp://www.engineersjournal.ie/wp-content/uploads/2016/06/Renewable-energy-300x300.jpgDavid O'RiordanElecbiomass,Department of Energy,electricity,energy
If decarbonisation is to be adopted in a manner that will meet the targets set out in the Paris Accord last year, burning of all fossil energy sources, including indigenous peat, will need to be eliminated completely as sources of electricity. To meet the shortfall created by a decarbonisation...