SIM 4890 Pumped Hydroelectric Energy Storage (PHES)

 Model Description

Pumped Hydroelectric Energy Storage (PHES) offers the advantages of conventional synchronised generators and thermal power plants while operating as a renewable energy technology. Additionally, PHES is highly versatile, capable of functioning as both a consumer and producer of energy depending on its mode of operation.

In consumption mode, the generator operates as a motor, driving the turbine to act as a pump that transfers water to an upper reservoir. This process converts electrical energy into gravitational potential energy.

In generation mode, water flows back through the turbine, driving it to generate rotational energy, which is then converted into electrical energy by the generator. Regardless of the operational mode, PHES contributes inertia to the grid when connected, enhancing overall grid stability.

However, unlike fossil fuel-powered thermal plants, PHES development is constrained by geographical and geological factors. Suitable sites require specific rock formations for constructing large caverns to house process equipment, as well as the presence of two natural reservoirs at differing elevations. In the UK, viable locations are limited primarily to North Wales and West Scotland, restricting the total energy storage capacity of PHES within the country.

As with many renewable energy solutions, PHES is not a universal answer but plays a critical role in a diverse and sustainable energy portfolio.

Learning Outcomes

• Process Overview.
  • Understand basic principles of PHES
  • Understand grid transition problems as a cause for adopting energy storage
  • Understand upstream and downstream processes
• Unit Overview:
  • Understand the basic principles surrounding pumped hydro energy storage being:
    • Gravitational energy storage.
    • Hydraulic energy conversion into rotational energy.
  • Understand how the unit integrates with the grid.
  • Electricity generation.
  • Grid conditions.
• Economics:
  • Understand how the economic model of PHES works
  • Understand the capital costs of PHES
  • Understand the OPEX costs of PHES
• Procedure and operations:
  • Understand the startup and shut down procedures.
  • Understand what safety considerations are made and the reason for them.
• Stretch:
  • To use your understanding of pumped hydropower energy storage to answer questions