Alternative Renewables - Waste to Energy

Dates : 12th and 13th January, 2019 [Source SEM-O] 

As the renewable energy programme has proceeded in Ireland without any form of supporting analysis, there has never been a proper economic assessment of the cost of reducing carbon emissions, using wind energy or any of the other ten sources of renewable energy listed in Directive 2009/28/EC.

Indeed, of the eleven different sources of renewable energy defined in the 2009 Directive, many are of a diffuse nature and more suited to being applied for heat energy rather than the generation of electricity. An example of this being the use of solar energy for water heating, which is a simple technology approach, such as circulating water through evacuated glass tubes.

Typical well-installed systems provide up to 60% of hot water demand over 12 months [SEAI].

The cost effectiveness of this approach can be determined from the fact that such installations were in use even before grants for their installation became available, as could also be said in relation to biomass (wood based) heating systems and aerothermal and geothermal systems for space heating.

If we consider a Waste to Energy (WtE) plant, the waste is combusted at a minimum temperature of 850 ⁰C producing in the boiler high pressure steam for electricity generation and hot water for use in district heating. Some 50% of the waste is of biogenic origin (biomass) and therefore 50% of energy produced is from a renewable source.

If this waste had instead gone to landfill, the biogenic fraction would have rotted and produced methane, which is a global warming gas with a Global Warming Potential (GWP) of 28 – 36 over 100 years. In other words it is some 28 to 36 times more potent than carbon dioxide. While the landfill gas collection system would have captured some of this methane for combustion in gas engines, figures show that of the order of 40% is directly released to atmosphere. In a WtE plant, the heat and mass balance shows 810 kWh of electricity produced per tonne of Municipal Solid Waste (MSW) combusted with about 0.72 kg biogenic CO2 and 0.53 kg fossil CO2 per kWh of direct emissions.

In the same timeframe that a 2004 report by ESB was stating that utilising a low penetration of wind energy to reduce a tonne of carbon dioxide was €120, it was being reported that the cost to avoid 1 tonne of CO2 with WtE was about €43, whereas the costs to avoid 1 tonne of CO2 with (other) biomass was €80. Indeed, if district heating systems are used in addition to solely electrical outputs, then this WtE CO2 avoidance cost reduces to the range €7 to €20.

It is therefore very difficult to reconcile these values with the claims made by many greens in Ireland, which are provided without any supporting evidence, that wind energy represents Ireland’s “cheapest renewable electricity resource”. But there is also evidence that increasing amounts of wind energy is discriminating against other forms of renewable energy.

The figure at the top of this article shows the relevant capacity factors for wind energy in Ireland and a Waste to Energy plant in Co. Meath over two days in January 2019. This facility treats some 200,000 tonnes of MSW per annum, with an electricity output of 18 MW, which was until recently a continuous output, with over 50% being classified as renewable. Outside of a short annual maintenance period this output is continuous so the WtE developer could in this case justifiably claim that this 18 MW is “enough to power more than 22,000 homes”

Yet there was so much wind energy on the grid on the 12th and 13th January that other generators had to be taken off line and kept on hot standby ready to ramp up, when the inevitable happened and the wind dropped. This can be clearly seen in the graph, where the WtE plant had to be taken off the grid for extended periods. However, such a waste to energy plant can’t be simply throttled back, the waste is still arriving and the furnace temperature has to be kept at a minimum of 850 ⁰C. Instead the steam generated simply has to be dumped into the plant’s cooling system rather than be used to generate steam. Not only is this a loss of revenue to the WtE operator, but it is reflected in resulting higher costs for waste disposal of those using that facility.

It could be argued that discrimination is occurring, in that renewable energy produced at the WtE plant, in a far more reliable and cost effective manner, now has to be dumped to facilitate ever more wind energy being placed on the grid. Wind energy, which by its highly variable and intermittent nature is deeply flawed for the production of significant amounts of electricity. Indeed, as is shown above, this wind output basically isn’t there when it is needed for days on end and then it floods the grid for a short period with high inputs. This can only be managed by discriminating against other users, including those which are lower cost and more reliable renewable inputs. It is also fair to say that this is what you get, when you allow a ‘wild west’ of wind farm developments, without any analysis, without any assessments or without any of the legally required rules to ensure that authorisation is transparent, proportionate and does not discriminate between individual renewable technologies.

Reference WtE cost €43 per MW to avoid 1 tonne of CO2 :

https://www.powerengineeringint.com/articles/print/volume-15/issue-5/features/waste-to-energy-energy-no-time-to-waste.html

Switzerland and Sweden Used as Models for Irish Carbon Tax

A Benchmark for the Carbon Tax, no Benchmark for cheap electricity  

As part of a comprehensive policy package, carbon taxes will have a central role in guiding the energy transition by providing the economic incentive to switch from high-carbon to low- or zero-carbon technologies and products. In Ireland, the Climate Change Advisory Council has recommended a phased increase in the carbon tax from the current €20 per tonne to €80 per tonne by 2030. In terms of benchmarking, it is worth noting that some countries already have carbon taxes at the upper end or even in excess of this range, with the Swedish carbon tax currently at $139 (e112) and Switzerland at $101 (e81).

The Central Bank have now thrown their weight behind the sudden political push for an increase of the carbon tax in Ireland. Their recent report about climate change and it's alleged impacts on the economy fail to address the issue of the unsustainable levels of government and private debt in Ireland, which allow us to live far beyond our means and consume resources at a far greater rate than previous generations. There is no mention of unsustainable government spending and the bloated welfare state (The cost for a new hospital in Dublin has risen from €400m to nearly €2bn, welfare spending still stands at €20bn despite lowest unemployment for over a decade).

The Central Bank fails to understand that emissions are coupled with economic growth so that if climate change were really having an impact on the economy, we would be seeing economic decline right now, followed by a consequent reduction in emissions. They make the observation that 1991-2016 temperatures were higher than the period for 1960-1990, which actually supports the natural cyclical theory of climate change rather than the man made theory.  They also claim that insurance payouts due to extreme weather events are up. The 1940s were perhaps the worst decade for flooding and crop devastation in recent history but I can find no evidence that there were any insurance payouts at all. But I want to focus on one particular part of their report, the carbon tax. 

The purpose of the Central Bank presentation on climate change appears to be to groom Irish people for more taxes, specifically carbon taxes. 

They present Sweden and Switzerland as models for Ireland to follow in this regard.  What they fail to state is that Sweden has electricity prices at least 25% less than Ireland. But more importantly, Switzerland, which has a carbon tax equal to that proposed by Irish politicians, has had one of the lowest electricity prices in the world for many years, roughly half that of Ireland, which now ranks as one of the most expensive countries for electricity in the world.  Switzerland generates most of it's electricity from hydro and nuclear (as does Sweden). How is it that Ireland's indigenous wind industry cannot compete with Swiss hydro, an indigenous renewable source that does not lead to high Swiss electricity bills ?

The examples of Sweden and Switzerland actually undermine the central banks case for more carbon taxes in Ireland as it shows that we are already paying comparatively much higher for energy. A carbon tax similar to what was introduced into these countries could make Ireland the most uncompetitive country in the world for energy with actual knock on impacts for our economy far worse than "climate change". 

One could have perhaps made a better case for the carbon tax if wind energy had led to the cheap energy revolution that Irish people were promised.  But as we all know that never materialized.

https://ec.europa.eu/eurostat/web/products-eurostat-news/-/DDN-20180807-1

Is Offshore Wind the Answer ?

ESB are planning to develop a massive 330MW wind farm off the east coast of Ireland. Will offshore wind be any different to onshore wind ? The experience in Denmark should be useful. The capacity factor for offshore wind in Denmark is around 43% which means the output will certainly be much greater than onshore wind in Ireland (which has a capacity factor of about 28%). 

But will offshore wind compliment wind energy? If the peaks in offshore wind occurred during the lows in onshore wind, then that would be very useful. This would result in a smoothing out of the intermittent profile of onshore wind we are so familiar with. We could call such a renewable energy source a "complimentary source". 

An example of a strong complimentary source would be perhaps solar energy, where during hot calm conditions such as last summer, solar energy would begin to peak just as wind energy fizzles out. In this case, we could say that solar and wind are negatively correlated, which indicates that they are strong complimentary sources.

To establish whether offshore wind is a strong or weak complimentary source, we can once again look at the data from Denmark, which has about 8GW of offshore wind capacity installed. In 2017, Euan Mearns analysed three years worth of data for both offshore and onshore wind, and found that the two are well-correlated (R squared = 0.71 for hourly data, 1 is a perfect correlation). This means that offshore wind is a relatively weak complimentary source. When the wind is blowing on land, chances are it's also blowing out at sea (and vice versa). 

Hourly onshore (red) and offshore (blue) wind generation with total generation scaled up to meet total demand, Denmark, 2014-2016 (from Euan Mearns).

So this means that power stations will still need to be ramped up and down as before. Offshore wind, like onshore,  will be incapable of replacing power stations, meaning its usefulness will be limited.

References: http://euanmearns.com/can-offshore-wind-be-integrated-with-the-grid/