Padd Energy

Integrating Energy Management with Industrial Processes

In Padd Energy’s experience, energy management on industrial sites is frequently considered separately and distinct from the actual industrial process itself.

This is a mistake but it is often due to organisational barriers. For example, the remit for ‘energy’ can reside in a different corporate function to ‘production’, meaning the upside rewards (i.e. reduced energy bills and reduced carbon emissions) do not directly benefit the business units that bear the risks of an ill-conceived energy strategy intervention.

Furthermore, a business’ core operation is rightly seen as sacrosanct and anything that risks production output (which to some is implied by the term ‘energy management’) is often given short shrift at Board level.

However, at Padd Energy we advocate a cross-functional approach to energy management for two simple reasons:

  1. All stakeholders, from the energy team, the environmental compliance team, the procurement department and crucially the production business units, must be engaged to ensure requirements are properly captured and risks eliminated or efficiently transferred through the project lifecycle of concept – purchase – installation – handover & operation. If that is achieved, all teams in the eyes of the Board are equally strong advocates of a solution that is often capital intensive and/or potentially business disruptive.
  2. Because production is likely to be the biggest source of energy demand on a site, it makes absolute sense to start here. And in our experience, production technology innovations can actually be much more cost-effective than conventional energy management technologies. Below, we look at one such example.

Phase change material (PCM) thermal storage

Padd Energy have recently been working with a global food production company to produce an energy strategy to meet their zero carbon ambitions. #makingnetzeroreal

In developing the strategy we looked at a number of process sites within their portfolio, of varying scale and production type, and assessed different technologies to optimise energy consumption and reduce carbon emissions.

Naturally we assessed conventional power generation and storage technologies (such as Li-ion batteries) but, recognising the extent of cold storage facilities within the portfolio, we considered a well-established technology known as Phase Change Material (PCM) thermal storage. Our analysis showed that when coupled with a facilities’ power, heating and cooling systems, PCM storage can offer substantial benefits over more conventional energy storage solutions.

Basic Principle

A PCM material is a substance which releases or absorbs sufficient energy at phase transition, typically from solid to liquid, to provide useful heat/cooling. In a cold storage facility, the PCM is stored within modules above the stored product.


When heat enters the facility, the thermal energy is captured in the PCM modules, rather than in the stored product. This is because the PCM is efficient at capturing thermal energy whilst the PCM is undergoing a state change from solid to liquid.

The important feature of a PCM compared to, say, a conventional hot or cold water store, is that the energy is released and absorbed at a constant temperature.  With selective blends of the working material, the temperature at which the energy is absorbed and released can be varied to suit the particular application.

A refrigeration system operates more efficiently at night due to lower external temperatures which can typically improve the chiller efficiency by about 2-3% for every 1°C drop in outside temperature. Also, electricity costs are usually cheaper overnight thus further reducing the running costs. Therefore, savings can be made by ‘freezing’ the PCM overnight. When energy costs are high during the day, the refrigeration equipment is run at a lower capacity and the PCM modules provide cooling to the facility. A further benefit of using predictive control to operate cold stores using this cycle is that it has been shown, through modelling, that up to a further 10% reduction in energy consumption can be achieved by utilising the refrigeration at full capacity overnight and avoiding less efficient part loading of the plant.

Integrating a Production Technology with an Energy Management Solution

As stated earlier, Padd Energy advocate a cross-functional approach to optimising an industrial site’s energy usage.

In our food production site example, a large solar PV installation may generate more electricity than the facility needs, particularly for low-rise, large roofspan cold stores in summer months. Rather than exporting the electricity back to grid, it could be beneficial to use the excess power to increase the running capacity of the refrigeration equipment in order the freeze the PCM. The PCM modules could then provide cooling to the facility at night when there is no PV generation, resulting in reduced carbon emissions and greater economic benefits to the client.


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