Water pumps get in on the balancing act

Dŵr Cymru Welsh Water is a not-for-profit water company committed to serving its customers. Thanks to demand side response (DSR), it has found that managing its energy demand more flexibly means it can do the right thing for its customers and the country. Mike Pedley, Head of Energy for Welsh Water, explains more.

At Welsh Water we have a very wide strategy to invest in energy efficiency, energy generation and indeed DSR and other forms of tariff optimisation. Our not-for-profit model helps the company take a long term view when it comes to investing in low carbon and sustainable technologies which will run for many years and provide long term benefit for our customers.

Currently, we have some 56 sites generating renewable energy, which includes about 6MW of solar and 14MW of hydro. In addition, we’ve got around 11 anaerobic digestion sites. We plan to continue rolling out renewable generation as long as it delivers acceptable returns for the company and our customers.

A flexible approach

DSR is also something we’re doing more of. We’re aware that it is increasingly important to National Grid, and therefore the UK, to help balance the system cost-effectively, but from our perspective it’s a potential way of getting financial benefit from using our assets flexibly. Thanks to our not-for-profit model, if we benefit from it, then so do our customers.

We’ve contracted with National Grid directly for a couple of their DSR schemes (last winter’s Demand Side Balancing Reserve and this summer’s Demand Turn-up) but following an open tender and successful trial, we’ve also started working with Open Energi on dynamic frequency response.

From our perspective it’s a potential way of getting financial benefit from using our assets flexibly.

The service helps National Grid with its second by second balancing of electricity supply and demand, and responds automatically to changes in frequency. So if there’s a sudden shortfall in supply, instead of National Grid asking a power station to ramp up, Open Energi can ask our pumps to slow down temporarily. Similarly, if there is excess power being supplied – say it was particularly windy or sunny – our pumps could increase their consumption to alleviate pressure on the grid and ensure no energy goes to waste. The key thing for us is our equipment is in control, and we set the parameters within which it can respond. We have found that if our pumps operate a little faster or a little slower for a few minutes at a time, that doesn’t impact our processes or customers.

What next?

Right now we’re targeting 25 sites and expect to have around 5MW of flexible demand. If that roll-out proves successful we’ll look at other assets to see whether we can expand its use. Not all of our assets are suitable but there are some that work well with this technology and I am sure that the same is true of a lot of businesses. I would expect more companies to adopt this type of technology for some of their assets. Increasingly in the UK now, companies can benefit from using their assets as flexibly as possible and that also helps the country.