Sunday, November 06, 2016

Electricity Demand Response - The UK's Best Hope for Keeping the Lights On as Government Fails to Replace Power Station Closures

Does the term "electricity demand response" mean anything to you? Ever wondered how it is that every year the UK closes coal and old nuclear power stations, and yet so far, even in the coldest winter weather the power has stayed on?

Increasingly, the reason is going to be the use of a technology known as electricity demand response. The concept is simple. Why maintain old, dirty and inefficient  power stations at the end of their useful lives, just to power them up for a few days annually during the coldest weather, if it can be avoided, If you can get power users to stop consuming their power for short periods, and pay them for the inconvenience wouldn't that be a better solution?

Here is what the Consortium for Energy Innovation in the US, have to say about this:
"To avoid unnecessary investments in transmission and generation resources, a good solution is to apply Demand Response programs to reduce the demand for electricity at peak hours, when generating electricity is more costly. Customers do not see how the electricity prices change on the real-time market, since most of them pay a flat rate based on the average price of electricity, therefore Demand Response programs can offer incentives to consumers to reduce their usage at peak hours, through rebates or as a response to higher electricity prices. For the residential customers, these programs yield positive results because users reduce their load at peak hours and, in some cases, they shift their usage to lower price periods. For industrial customers, the Demand Response programs there have not been as numerous experiments as for the residential sector, but they still yield a positive usage reduction." via implications-of-electricity-demand-response-experiment-structures-for-commercial-customers

Of course, a simple idea like this will require some truly revolutionary technology to make it work. Work will be needed both in physically modifying power grids on the ground, to accommodate the far more widely fluctuating demands for electrical power to flow around the power grid system and in cyberspace to instantaneously predict and control consumer power loads.

A whole new area of research and development has emerged, and the paragraph below provides a flavour for the topic:
"Electricity demand response is considered a promising tool to balance the electricity demand and supply during peak periods. It can effectively reduce the cost of building and operating those peaking power generators that are only run a few hundred hours per year to satisfy the peak demand. The research on the electricity demand response implementation for residential and commercial building sectors has been very mature. Recently, it has also been extended to the manufacturing sector. In this paper, a simulation-based optimization method is developed to identify the optimal demand response decisions for the typical manufacturing systems with multiple machines and buffers. Different objectives, i.e. minimizing the power consumption under the constraint of system throughput, and maximize the overall earnings considering the trade-off between power demand reduction and potential production loss, are considered. Different energy control decisions are analyzed and compared regarding the potential influence on the throughput of manufacturing system due to the different control actions adopted by throughput bottleneck machine". via Elsevier-simulation-based-optimization-of-electricity-demand-response

At one level this could be seen as an easy way out for politicians unable to reconcile the need for new (low carbon emissions) power stations which they don't want the nation to invest in, and which become beset with inevitable the public objections to all new power station projects.

Of course, as the proportion of highly changeable renewable energy sources into any power grid system rises, the distribution systems these feed into will in any event have to be adapted to much more rapidly bring in additional power sources. It will also rapidly disconnect them again after peak-demand periods, in response to changes in demand due to weather and temperatures.

There are good reasons for adopting new electricity demand response technology as the idea has great synergies with efforts to carbonise energy consumption.

It may even help indirectly to reduce the cost of water supply, and sewage treatment. That is because the water industry can fairly easily adopt systems which shed their loadings for short periods, and yet still provide their water services. Reservoirs and service tanks can be refilled after peak electricity demand periods cease, and if necessary equipment can be adjusted to work a percentage point or two harder when it is working, without noticeable effects on performance. Up to a point, the water industry is keen to co-operate because the costs of doing this, will be likely to be significantly less than the incentive payments made by the electricity supply companies.

Electricity Demand Response and the Anaerobic Digestion and Biogas Industry

Disadvantages of Electricity Demand Response Implementation

For the anaerobic digestion and biogas industry, the downside is that implementation of demand response technology reduces the absolute necessity for constant 24/7 electrical power production which AD Plants, are ideally placed to supply.

That means that the otherwise dire consequences to the national economy of power station closures, can possibly be avoided while still decimating previous renewable energy incentives. In particular we refer to the recent UK reductions in AD plant construction grants, tax relief, and energy production grants in various forms

With total UK AD Plant capacity now predicted to rise to in the region of 10% of total total electricity supply over the next 2 years or so, the contribution the AD industry could add further to this is of real consequence,

Advantages of Electricity Demand Response Implementation

On the plus side, there is an opportunity for existing AD Plant operators to bid for demand response contracts. AD Plant operators can undertake to supply enhanced output during peak periods by running at full output, and /or shedding their own loads (including on-farm).

Any site owner, including AD Plant owners with additional capacity to feed electrical power into the grid can elect to install additional diesel generation capacity purely to run them up to supply power during peak demand periods.

Finally, AD plant operators may find it increasingly advantageous to add battery energy storage to their AD facilities, and to inject stored battery power into the grid exactly as needed by the power companies.


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