As Affinity Water completes solar array pilots at its Chertsey and Walton treatment works, the firm’s head of energy management Greg Cameron reflects on the challenge of developing a new energy strategy to simultaneously drive performance and weather the highest increase in bills on record.

Since April, Affinity Water’s combined arrays at Chertsey and Walton have generated more than 1,095 MWh of electricity – capitalising on the UK’s summer heatwave to produce a daily average of 7,640kWh of electricity throughout June, saving more than £215,000 in energy costs in the process.

The 1,820 solar panels at Affinity’s Chertsey treatment works – which processes 45 million litres of drinking water per day – have produced up to 21% of site energy since energisation and is projected to achieve 12% as an average for the full 12-month period.

Chertsey array in numbers

  • 1,820
    Number of solar panels installed.
  • £144,961
    Energy cost savings to date, using the 22/23 tariff.
  • 158 tonnes
    Carbon savings to date.
  • 777,690 kWh
    Energy produced since energisation

The 1,216 ground-mounted solar panels installed by UPOWA – formerly HBS New Energies – at Affinity’s Walton works have been producing up to 18% of the site’s energy versus 2021 requirement and are projected to achieve 11% as a yearly average.

Walton array in numbers

  • 1,216
    Number of solar panels installed.
  • £70,663
    Energy cost savings to date, using the 22/23 tariff.
  • 76.7 tonnes
    Carbon savings to date.
  • 379,096 kWh
    Energy produced since energisation.

Following this pilot phase, carried out in partnership with Centrica Business Solutions and UPOWA, it’s now expected that the two Surrey-based solar arrays will generate up to 1.2MW of solar energy to help power operations – on average, over 4,200 kWh per day over a full 12-month period, or the equivalent to the power demand of 350 four-bed detached properties.

Ultimately the firm, which provides 900 million litres of water daily to more than 3.6 million people in parts of Bedfordshire, Berkshire, Buckinghamshire, Essex, Hertfordshire, Surrey, London, Essex and Kent, hopes to increase this combined output to between 20-23.5MW annually – slashing the firm’s carbon footprint by up to 95,000 tonnes over a 20-year asset life and offering an estimated £4.38 million in savings based on current electricity tariffs.

Preparations are also underway to construct arrays at a further 28 sites during phase two of Affinity’s £29 million solar rollout, as the firm strives to be operationally net zero across scope one and two emissions by 2030 and net zero by 2050.

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Greg Cameron: ‘Need for new ideas and opportunities’

Energy is the second largest cost to our business and has increased significantly in recent months due to global supply factors – it is also a significant contributor to our carbon footprint.

We have split the different areas of energy into three workstreams – ‘build’ which is our renewable programme, ‘buy’ for the purchasing of electricity, and ‘manage’ which is my workstream and is responsible for energy efficiency and performance.

As everyone will be aware, the last 12 months have given rise to the highest increase in energy bills on record, this doesn’t just affect households but also commercial businesses such as ourselves. In 2021-22 we have seen energy unit prices increase by almost 50%, which equates to around £15 million per year.

This cost pressure alongside the need to transition to a net zero business by 2030 means that saving energy is essential for our business both now and into the future.

I’ve been in my role as head of energy management at Affinity Water for about a year and I’m really enjoying the challenge of developing a new strategy to drive our energy performance. As part of our energy strategy, I am currently developing our medium and long term plans for how we optimise our performance to minimise the energy we consume.

These plans will look at our asset infrastructure, improving energy data and insight, building resilience and developing our people and culture. These plans are ambitious and look for significant investment in our assets, systems and people so we can operate as efficiently as possible. The energy strategy will be a key feed into our net zero carbon strategy as well as the overall business plan for PR24.

In the short term we have an immediate need to become more energy efficient. Through our budget setting process we have included a £500,000 efficiency on energy which we will need to deliver this year. Achieving this target will require us to work together across departments to identify new ideas and opportunities for site improvement and system optimisation and then drive these through to delivery and benefit realisation.

One of the first activities I have focussed on is improving our energy data and insight. Working with our IT team, we have created our first Energy and Carbon Performance Dashboard (EPCD). This tool details the energy, carbon and cost performance of over 140 of our production sites as well as totals for each community area and the overall business. This dashboard uses telemetry data to show how performance changes on a daily basis and compares the volume of energy used against the number of megalitres of water produced.

My expectation is that this will be a vital tool for how we manage and optimise sites and wider communities to make sure we are minimising energy consumption as much as possible. This will enable insight into the cause and effect relationship of operational changes and inform us in finding the most optimal way of operating our business. I’m looking forward to seeing the improvements that we can deliver through this approach.

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