UK’s Solar Power Generation

The UK’s solar panels generated more electricity than coal for the first time. On Saturday 9 April, solar generated 29 gigawatt hours (GWh) of electricity, 4% of the total power used that day and more than the 21GWh output from coal (3% of demand). This pattern was repeated on Sunday, with solar (6%) outpacing coal (3%). In reality, the coal consumption was unusually low – but this does demonstrate some of the major changes and improvements being made to the UK’s power supply.

Our Quarterly Rant: The fate of UK energy supply

Coal power generation accounts for about 20% of our total requirement. The UK has committed to remove coal from our mix of power sources by the mid-2020s. So what will fill the gap?
In the right conditions; power from wind, solar and hydroelectric generate nearly 20% of the UK’s requirement with corresponding reduction of ‘carbon intensity’ of our electricity supply. By their nature, these sources rely on the weather – and so are intermittent and require a backup of some kind. Although there is plenty of new wind power to come, we sit shamefully toward the bottom of the league table for renewable energy deployment. With the painfully slow progress of new nuclear and gas power construction, a major ‘energy gap’ looms when coal and ageing nuclear generators go off-line within 10 years.

Our DECC Minister had hardly stepped off the plane from the Paris climate conference before she announced an end to onshore wind development, huge cuts to solar, scrapping of carbon capture research and cessation of sustainability measures. In the same breath she announced enhanced support for oil and gas producers – and even subsidies for diesel power generation! DECC are saying one thing in public and moving 180° from this direction in reality.
It seems that coal power will be replaced by gas derived from dwindling domestic resources, imports – and shale gas. This will allow DECC to claim a reduction of CO2 output, albeit through replacing one fossil fuel with another. The amount of economically producible shale gas in the UK is entirely unproven and highly unlikely to make more than a fleeting difference to our strategic gas resources.

Nuclear power, a British invention, must be a major part of our future (zero carbon) power supply. We are financially guaranteeing the Chinese and French to design, build and operate new reactors. Do we really know enough about the Chinese economy, or our relationship with the Chinese state in 10 years, let alone 50 years, for this to be a safe, rational solution? Why we cannot trust British engineers to provide nuclear power, given the same degree of financial backing, is quite beyond me.
The potential for domestically engineered tidal power is untapped – and enormous. We live on a windy island in a large ocean, so tidal energy is always available and is zero carbon, secure, predictable, can provide thousands of UK jobs and has no waste product. Why are we not building them by the dozen?

A criticism of renewable heat and power technologies is their need for subsidy to incentivise uptake. It is not widely known, and certainly not broadcast by government, that nuclear and fossil fuel technologies are subsidised to a higher degree than renewables ever could be. In fact, just this week the government have granted £250M to the oil industry in Scotland to prop it up while oil prices are low. (the oil industry won’t pay this back when prices rebound – so why is the tax payer baling out oil companies?!).
The November budget announced (quietly) that the renewable heat incentive (RHI) would continue to be funded up to 2021 – although with a cut of up to 40%. This at least gives renewable heat providers a degree of stability – and we are already seeing an increase in demand for ground source heat pumps.

The ‘anti-renewable’ stance and continued delay of nuclear construction puts at risk our ability to generate our own power. We should not be in this position. We have all the engineers and natural resources we need to provide our own sustainable heat and power.

Feasibility assessment of a large water-source heat pump for Nottinghamshire County Council

Carbon Zero Consulting completed the Stage 1 feasibility and options assessment for a potential renewable heating system to replace gas boilers at Nottingham County Hall on the river Trent.

An assessment of river flow and temperature confirms the Trent is certainly capable of providing sufficient water for an open-loop water source heat pump (WSHP) to replace the majority of heat currently provided by gas boilers.

Our detailed report on the viability of this system covered initial aspects of the existing heating and heat distribution system, water intake and discharge works in the river and regulatory issues.

Our findings were presented and well received by Councillors and the engineering team. We have now been asked to make proposals for the 2 Stage feasibility assessment.

UK Renewable Power Generation and Grid Carbon Intensity

Since 2nd June 2015 we have been monitoring the contribution of renewable power generation and carbon intensity of the UK National Grid. A ‘spot’ reading is taken at midday each day.

The addition of wind, solar and hydro-power to existing power generation (gas, coal and nuclear) is starting to make real inroads into the average carbon intensity of the national grid (the amount of CO2 emitted for each unit of electricity generated).

Coal power stations are to be phased out of the UK by 2023 meaning that it is likely that more gas power stations will have to be constructed (new nuclear power installations will take a minimum of 10 years to come on line). The current UK government has put a stop to further onshore wind installations, but there are likely to be more constructed offshore. Likewise, the rate of installation of solar PV, ground source and biomass systems will slow radically with the planned major reduction of tariff payments.

Wind, solar, hydro and nuclear power do not emit CO2 to the atmosphere, while coal and gas emit CO2 with coal being significantly worse than gas.

Graph of UK Grid Carbon Intensity (Nov 4)

As stated in the last article the Carbon Trust states that in all calculations 500 gCO2/kWh is to be used for computation of carbon emissions for heat pumps. However, the value found over the past 4 months is significantly lower than that with an average closer to 385 gCO2/kWh. The result of this is that Ground Source Heats Pumps provide significantly greater environmental benefit than the data published by the Carbon Trust would suggest.

UK Turns To Diesel For Power

At the same time as destroying the UK renewable power industry and removing many energy saving initiatives, the UK is turning to diesel to meet an impending power supply crunch. You really couldn’t make it up if you tried. This Tory government is surely the most short-sighted and bone-headed ever. They have entirely lost the plot!

The UK is set to grant subsidies worth hundreds of millions to highly polluting diesel electricity generators (reports the Financial Times). The support, through the government’s capacity market auction, is designed to ensure the lights stay on. Yet in meeting this aim up to 1.5 gigawatts of polluting small diesel could receive up to £436m in grants. The plant would be only slightly less CO2-intensive than coal and emit several million tonnes of CO2 a year.

The Fate of the Renewable Heat Incentive

The UK’s stated efforts to reduce CO2 emissions rely on replacing coal (and later, gas) with power from nuclear, wind, solar and tidal generators. These sources of power are to be linked with massive uptake of electrically-powered low carbon heating technologies (heat pumps). The renewable heat incentive (RHI) was intended as a driver toward this aim to promote the uptake of low carbon heating.

Amber Rudd, our new DECC Secretary of State has hit the ground running and is wielding a very sharp axe! With the key UN climate event in Paris looming in December you might think our government would be paying urgent attention to our commitments towards reducing CO2 emissions. The Minister’s speech acknowledges no such urgency – instead she chooses to focus on how the UK’s response to climate change somehow fits within the Chancellor’s drive for short-term and short-sighted savings. The Green Deal, feed-in-tariffs, zero-carbon homes and other recently installed measures are to be cancelled or ‘reviewed’. Although no changes have been announced, we can be confident the renewable heat incentive (RHI) will also be under review.
To date, uptake of renewable heating has progressed in a surprising direction with technology selection based on RHI income, and not sound engineering principles. Figures show that over 90% of all non-domestic RHI applications have been for biomass systems. This is clearly unsustainable. This skewed market is being addressed by recent reductions of the biomass RHI tariff allowing (ground source) heat pumps to compete.

Bearing in mind that the entire RHI budget accounts for less than 1% of DECC’s annual spending (96% goes toward nuclear decommissioning); any future reduction of the RHI would be a wholly ineffective response to Treasury pressure for cuts. However, the RHI in its current form has not achieved some of its intended aims and so it is right to consider some changes and improvements.

The RHI should be retained and improved to support an emerging, high technology engineering sector. We see a blend of ‘carrot and stick’ as being the way ahead to promote renewable technologies, meet emissions targets – and reduce cost to the Treasury.
The below should also be given due consideration:

• Addition to the RHI of an up-front payment to help with the higher capital costs associated with renewable heating systems.
• A renewable heat tariff paid over a shorter time frame. This reduces the government’s long term obligations – which is seen as a factor for opposition to FIT and RHI payments.
• Tightening of (Part L) Building Regulations and introduction of ‘Minimum Energy Efficiency Standards’ for non-domestic buildings. At no cost to the Treasury, these changes would force energy efficiency improvement of the UK’s housing and commercial building stock and promote uptake of renewable technologies.

UK Power Generation Grid Carbon Intensity


The UK is committed to phasing out power generation by coal (and much later gas) and to increase the contribution from nuclear power and renewable technologies (wind, solar, hydroelectric and tidal). The goal is for power generation to become ‘zero carbon’ by 2050 when all power will be generated by renewable and nuclear means.

Since 2nd June 2015 we have recorded (once per day) renewable power production and the ‘carbon intensity’ of the UK National Grid. The graph shows the percentage of total power generation being met by renewable energy (wind plus hydroelectric) and the resulting carbon intensity of energy produced.

It can quickly be seen how renewable energy generation impacts directly and significantly on the Nation’s Grid carbon intensity.

UK Grid Carbon Intensity

We do not include contribution from nuclear power in the ‘Percentage Renewables’, but nuclear power is also a zero-carbon power generator. Currently, nuclear power provides about 20% of total power produced.

Continued reduction of grid carbon intensity will reduce the UK’s impact on the global rise of CO2 and average temperature. The benefit of lower grid carbon is further enhanced when used to heat our homes and businesses via electrically powered heat pump technologies, such as Ground Source Heating.

Currently, the Carbon Trust states that in all calculations of CO2 emissions from heat pumps, a grid intensity of over 500gCO2/kWh is to be used. However, our findings clearly show the average value is closer to 375gCO2/kWh.

We will continue to plot this data to show the beneficial impact of renewable power implementation.

Busy doing soil surveys!

There has been a bit of a rush on soil thermal conductivity surveys this month. We normally perform 2 or 3 a month, but we’ve done 5 already in July!
Our surveys provide in-situ measurement of soil thermal conductivity at the depth at which a proposed GSHP ground array is to be installed.
We successfully completed domestic scale surveys, a large golf club array near Durham, and another for a new poultry farm in Cheshire.
We are also working with De Montfort University in Leicester on an exciting new piece of research to assess heat storage in soils; we were asked to perform a baseline survey with excavation and measurements down to 2m depth on the 2 hottest days of the year …..a fine welcome to the world of Carbon Zero Consulting for our new recruit, Lawrence Scott!

Politics and ‘renewable hot air’?

Despite an election campaign that failed to mention UK renewable energy policy, the recent G7 meeting made a commitment to pursue ‘deep cuts in global greenhouse gas emissions’. Good news? Yes, probably, although cynics might suggest this does no more than delay commitments made previously to reduce emissions by 50% before 2050! Rhetoric will no doubt increase toward the ‘UN climate show’ in December; a major objective of which is to limit global temperature increase to 2°C.

John Findlay of Carbon Zero Consulting, explains ‘the UK’s efforts in reducing CO2 emissions rely on replacing coal (and later, gas) with increased power output from nuclear, wind, solar, tidal – and through massive uptake of renewable heating. The latter continues in a rather surprising direction. Recent figures show that 93% of all non-domestic renewable heat incentive (RHI) applications have been for biomass systems. On the domestic front the story is more mixed but shows that the predicted renewable market as a whole is well below where it needs to be.
Major changes are needed to the RHI to breathe life into the renewable heating market, to correct the imbalance of technology uptake and to allow movement toward the stated aims of the UK Climate Change Act.

Proposals to address these factors have been developed by the ground source heat pump association (GSHPA). These can be found at GSHPA_Manifesto Briefing. Findlay adds that “although recent reductions to biomass RHI will help the situation, we must ensure renewable technologies are selected on sound engineering principles – and not simply on short term RHI gain”.