Pumped Hydro
Table of Contents
Introduction
Life Expectancy: Over 40 years for the electromechanical equipment, and over 100 years for the dam.
Pro: 65-70% round-trip efficiency. Pumped hydro currently represents the highest capacity of storage in the world. Closed-loop pumped hydro storage present minimal environmental impact as they are not connected to existing river systems. Pumped hydro can help boost solar and wind project expansion which would otherwise be limited by storage capacity.
Con: Hydro pump facilities can only be build in places that already have the right topography, able to store massive amounts of water at high elevations with a body of water significantly lower than the storage site. Pumped hydro is also very expensive because of the high capital cost and labor to build the necessary dam, plus to install the pump/generator. Open-loop systems can harm species such as endangered eels.
Solution: Some research has gone into saline/underground pumped hydro, removing the need for traditionally needed topography, but this has proven to be problematic and expensive due to the corrosivity of saline water.
Fuel: Gravity, Electricity, & Water
Energy Education: Pumped Storage "is the process of storing energy by using two vertically separated water reservoirs.[1] Water is pumped from the lower reservoir up into a holding reservoir.[2] Pumped storage facilities store excess energy as gravitational potential energy of water. Since these reservoirs hold such large volumes of water, pumped water storage is considered to be a large scale energy storage system. These pumped storage facilities are moderately efficient, with a round-trip efficiency of about 65-70%.[3] The amount of energy stored depends on the mass of water pumped and the height difference between the reservoirs.
Pumped storage is a dispatchable source of energy since it can be deployed whenever demand is needed. It is often used to meet demand when intermittent, non-dispatchable sources, such as wind and solar power, cannot do so.
Currently pumped storage has the highest capacity of energy storage on the grid and accounts for 99% of bulk storage capacity in the world.[4] The United States alone has more than 20 GW of pumped storage capacity today with facilities in every region of the country.[5]
Over the past 70 years, there has been a steady increase in the number of pumped storage facilities around the world. Some examples of pumped storage facilities worldwide include:[6]
Bath County, USA (2710 MW)
Kannagawa, Japan (2700 MW)
Guangzhou, China (2400 MW)
Lac des Dix, Switzerland (2009 MW)"
Tools & Guides
Argonne National Laboratory: Valuation of Pumped Storage Hydropower "Valuation guidance and techno-economic studies for pumped storage hydropower"
Types of Pumped Storage
Closed-Loop
Open-Loop
Suitable Locations
Abandoned Mining Pits
Natural, High-Elevation Lakes
Especially on islands or other locations with naturally hilly or mountainous spaces, pumped hydro can make a lot of sense. The biggest issue probably being the need to asses life in the existing water body, to avoid heavily impacting any native species. For example endangered eels can easily get sucked into pumps, in which case it may make sense to create a new body of water to avoid harming the local species.
Underground with Saline Water
Benefits
The benefit of this is minimal impact at the surface level, specifically minimal space use. Using saline water means drinkable water isn't being used, and ecosystems that rely on fresh bodies of water aren't being impacted, or possibly killed by the pump system.
Drawbacks
Saline water is highly corrosive and underground saline bodies of water can have very different properties from non-saline water. These factors can impact equipment considerably, creating problems that are not an issue with traditional pumped hydro. This means higher costs and more frequent repairs or replacements.
Companies & Stations
International
Stantec "We have one of the largest groups of pumped storage specialists in the international consulting field. Our services extend from due diligence and initial site selection through project construction, commissioning, and operation, and they address the spectrum of issues that face project developers and owners throughout the project's life cycle."
Europe
UK
England
Dominion Energy: Bath County Pumped Storage Station "Powers approximately 750,000 homes"
North America
Canada
Alberta
Canyon Creek Pumped Hydro Energy Storage Project "owned and developed by TC Energy, will play a critical role in Alberta’s renewable energy future. The Project will have a generation capacity of 75 MW, which will provide up to 37 hours of on-demand, flexible, clean energy and ancillary services to the Alberta electricity grid, meeting some of the province’s future power demand with renewable energy sources.
This project will enable more intermittent renewable energy generation on the Alberta Interconnected Electrical System by generating energy during times of high demand, while also having the capability to store energy during times of low demand."
Organizations
Grants & Funding
North America
USA
The Climate Pollution Reduction Grants (CPRG) Program "provides $5 billion in grants to states, local governments, tribes, and territories to develop and implement ambitious plans for reducing greenhouse gas emissions and other harmful air pollution. Authorized under Section 60114 of the Inflation Reduction Act, this two-phase program provides $250 million for noncompetitive planning grants, and approximately $4.6 billion for competitive implementation grants."