Water & Wastewater Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/717366
www.wwtonline.co.uk | WWT | SEPTEMBER 2016 | 21 Close-Up Water and energy: demand response Energy in Demand Technology is opening the door for the water industry to make significant savings on energy costs via demand response, with little or no impact on its operations D emand response – the process by which large energy users agree to amend their consumption patterns to balance the supply capacity of the national grid – is an increasingly profitable opportunity for water companies. As the grid incorporates more variable, climate-dependent sources of energy - such as wind and solar – and fewer more easily-controlled fossil fuel power stations, there is a growing need for demand response because there is a greater chance of a surfeit or shortage of energy on the grid at any one time. As a sector which uses a lot of energy, much of it through operations which are not time-sensitive, the water industry is an ideal candidate for demand response and has been involved in it for many years. The degree of recent innovation and evolution in this field is reflected The increasing role of weather-dependent renewable energy is one of the factors behind the growing need for demand response JamEs BroCkEtt EdiToR WATER & WASTEWATER TREATMENT by the large number of available schemes to which companies are able to sign up – there are at least 15 distinct demand response programmes, most administered by National Grid but some also involving third party aggregators (see box). What's more, developments in technology are allowing more sophisticated forms of demand response which allow considerable flexibility in what they produce while making remarkably little difference to the end user. Rather than having to manually turn off or turn down an asset when given a signal, equipment such as pumps or blowers - controlled by variable speed drives - can be programmed automatically to ramp up or down at just a few seconds notice. Operators determine the pre- set limits within which the power use of each asset can fluctuate; when a dip in energy use is called for, each individual pump or aerator sees minimal difference in its operation, but when multiple assets are operating like this in lockstep, it adds up to a considerable energy resource available at a moment's notice. This type of 'frequency response' is usually handled by third party aggregators who contract with users on behalf of National Grid and control the process. It forms a key element of the Grid's 'Power Responsive' campaign, launched in June 2015, which aims to achieve rapid growth in demand response across the UK by 2020 to help moderate peaks and troughs in supply and demand and ease concerns over the country's future energy resilience. From the water sector's perspective, the financial potential for such tie-ups is considerable: it's estimated that the industry has around 500MW of flexible demand from pumps and aerators which could be harnessed, and when you consider that participating companies might be paid £100,000 per megawatt, one gets a sense of the scale of the opportunity. Frequency response Dwr Cymru Welsh Water recently signed an agreement with aggregator Open Energi to roll out frequency response across a significant chunk of its assets. Following an open tender and successful trial of Open Energi's Dynamic Demand technology, Welsh Water expects to provide an aggregate flexible demand of 5MW from 25 of its sites during the first phase of implementation.