Cost comparisons for energy storage technologies can be tricky
because they depend on several factors, including:
Project size and scale: Large-scale PHES facilities will naturally be more expensive than a smaller off-grid battery system.
Technology maturity: Newer technologies like gravity storage might have higher upfront costs due to being in earlier development stages.
Site-specific considerations: Factors like geographical features and construction requirements can influence the final cost.
However, here's a general comparison to give you an idea:
Pumped hydro storage (PHES): While mature and reliable, PHES has the highest upfront cost due to the significant civil engineering involved in building reservoirs and dams. Estimates range from $1,000 to $3,000 per kilowatt-hour (kWh) of storage capacity.
Lithium-ion batteries: Costs are steadily decreasing, but they still come in at a higher price point than PHES per kWh. The range can be anywhere from $200 to $600 per kWh.
Lead-acid batteries: The most affordable option, with costs around $100 to $200 per kWh. However, they have a shorter lifespan and lower depth of discharge compared to Li-ion.
Gravity storage: As a developing technology, cost data is limited. Estimates suggest it could fall between Li-ion and PHES, potentially in the $500 to $1,000 per kWh range.
Here are some resources for further exploration:
Lazard's Levelized Cost of Storage report: This annual report provides a detailed comparison of the costs of various energy storage technologies. You can find it by searching for
"Lazard Levelized Cost of Storage".
Articles from reputable energy websites: Look for articles from organizations like the International Renewable Energy Agency (IRENA) or the US Department of Energy (DoE) that discuss energy storage costs.
Remember, these are just estimates. The actual cost for a specific project will depend on the factors mentioned earlier.