Readers letters
I have read numerous articles on renewable energy and have observed the “rush for wind” with a wry bemusement. I believe in a balanced portfolio so therefore have to accept wind turbines for what they are; an interruptible supply of power that will contribute in part to our quest to use less fossil fuels... and create jobs.
The latest shift in renewable energy has seen investment in wave and tidal power. I’ve never bothered to do the calculations myself and pay scant regard to “commercial propaganda” which seems to dominate the assessments, but common sense suggests that there is at least as good a chance of this contributing at least as well as wind power.
However, the continual use of the term renewable energy when discussing renewable electricity is distorting the landscape. It is refreshing however to finally see an increase in attention to renewable heat.
Thermal use of energy below 100°C accounts for over 50% of the UKs energy according to DECC (excluding transport). It is therefore encouraging to hear of biomass uptake but once again when one digs a little deeper it is an industry that is self-perpetuating on it’s own propaganda. Surely growth that would result in over 80% of the mass consumed being imported can’t be right I thought to myself a few months ago. Common sense was supported with recent studies and one of the letters in PE, April 2012 by Mr Glover recounting that biomass was found to be more carbon intensive than coal. Again though from balanced perspective there has to be some merit but the mass importation really concerns me.
The latest trend that we are observing as a company is the uptake of large industrial heat pumps as reported in PE a few months back. Originally conceptualised by Lord Kelvin in 1982 the current high oil price seems to be creating a market, even before the RHI is considered.
The most pleasing aspect of this surge in interest is the novel ways in which heat pumps are being deployed. To date we have supplied units between 600kW and 14,000kW to extract heat from a fjord to deliver at 90°C for district heating, capture waste heat from a Norwegian dairy for green house heating, capture heat from the river in Zurich, extract heat from the harbour adjacent to an army barracks. The next wave of projects are likely to be squeezing more heat from existing combustion facilities (either gas or biomass) as well as utilising the heat in the return leg of district heating loops to allow system extensions. Whether we ever see a political will to utilise the waste heat from large district cooling facilities to be boosted to allow the desalination of seawater remains to be seen, but the technology is there, proven and ready to go. “Shovel ready” is the populist term I believe.
So what does this all mean for the electricity markets? Well on one level it will mean a larger draw on our stretched resources. However, with the thermal storage capacity of large district heating networks added to the equation, we might see some absorption of the peaks and troughs associated with interruptible supplies. Most heat pump industrial applications (not air source) will yield a 40% or higher carbon footprint saving. This suggests to me that we should accept the likely low price of gas, develop means of reducing our addiction to gas combustion for localised heating, increase our use of large renewable heating solutions and deliver the desired carbon savings by building a series of gas fired CHP with maximum heat recovery.
Concluding the thoughts on carbon footprint, and return on investment. We never undertake projects that don’t deliver on both accounts but with rising electricity prices unless the grid shifts to high efficiency CCGT (over 59%?) and keeps the cost of electricity moderate then we won’t see the necessary decarbonisation of our heating networks to free up the gas required for the CHP.
Catch 22? Not in my mind. It is a clear incentive to stop the waffle and make a pre-emptive and decisive intervention to allow a “macro” solution to prevail.
I look forward to independent comment on my simplistic views. Perhaps the IMechE should referee the debate!
Dave Pearson, Glasgow
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