Energy & Cost Impacts: Behind the Meter Energy Storage

Battery energy storage systems (BESS) have a number of energy and cost impacts for users:

  1. Energy Savings and Energy-Use Efficiency:
    1. Energy Savings: Building Energy Storage is not principally an energy savings measure. It can however reduce energy costs by shifting the electrical loads seen by the grid. It can also make more efficient use of any on-site solar generation.
    2. Peak Shaving/Peak Shifting: BESS can store energy during off-peak times (when electricity rates are lower, such as during peak solar generation) and discharge it during peak demand periods. Users can thus shift grid energy usage to times when electricity rates are lower, reducing energy costs.
    3. Backup Power: Batteries can provide a backup during outages, which can be crucial for critical systems or operations.
  2. Cost Impacts:
    1. Initial Cost: The upfront cost of purchasing and installing a battery storage system can be significant and is dependent upon the application. However, prices have been decreasing over time.
    2. Utility Incentives: Various programs offer incentives, rebates, or tax credits for installing battery storage, which can offset initial costs. Some resources include:
      1. https://www.energy.gov/eere/solar/federal-solar-tax-credits-businesses
      2. https://programs.dsireusa.org/system/program/ca
    3. Maintenance Costs: While generally low, there may be ongoing maintenance or replacement costs as the battery ages. Analysis shows storage capacity degradation over time that scales with the number of charge/discharge cycles, with modest dependence on climate zone.
    4. Storage Plus PV: Pairing battery energy storage with onsite renewable generation can increase cost benefits by storing excess generation for later use. This can reduce or eliminate the amount of energy put back on the grid (which is has lower monetary value than the energy taken from the grid), which maximizes the value of the energy generated onsite and can reduce energy bills.
    5. Cost Savings Example: Assuming that energy is stored when electricity costs $0.30 per KWh, and is consumed when electricity costs $0.70 per kWh, and a roundtrip efficiency (kWh delivered/kWh stored) of 80%:
      1. Average Revenue=800 kWh×0.70 $/kWh = $ 560
      2. Average Cost=1000 kWh×0.30 $/kWh = $ 300
      3. Savings per 1000 KWh of storage capacity per charge/discharge cycle = $260
      4. Note that the round-trip efficiency was found, based upon detailed simulations, to be relatively insensitive to climate
    6. Other Economic Implications:
    7. Increased Property Value: Battery systems can enhance property value and appeal, particularly in areas with frequent power outages or high electricity rates. There is currently not enough data comparing first cost to property value changes

    Overall, while the initial cost is high, the cost savings, along with added resilience, can justify the investment in battery energy storage.