The Power of Battery Storage

This is an excerpt from the minutes from our meeting in October 2018

1.1  Connected Energy use second life car batteries (Renault, Nissan, Jaguar Landrover) for future life.  We work with high energy user to help them with energy use and costs.

1.2  The new energy infrastructure will see more renewables.  But these can be intermittent and sometimes there is too much generation.  Battery storage provides load to the user or a sink to the Grid at times of stress: they can absorb over generation or over demand and balance the grid through frequency / demand response at 50hertz.

1.3  There are several opportunities for energy users:

a)    Behind the meter, where a modularised container battery sits onsite (eg at a leisure centre or LA HQ).  The benefits are TRIAD avoidance (leave things as they are and the battery provides the load rather than the grid; accounts for 6.8% of the average electricity bill), TRIAD benefit (return excess to the grid and get a small payment), offset DUOS charges (account for about 16% of fixed electricity bill charges) and capacity market charge avoidance. 

We’d:

i)              Look at your half-hourly usage profile

ii)             Match this against TRIAD & DUOS

iii)           Match the batteries to your profile and revenue

We:

·         Run the batteries conservatively to prolong life (c 8 year onward life)

·         Fully charge from the grid if there’s new renewables

·         Discharge during TRIAD

·         Then cycle back

This process has about a 5.5year payback

b)    Aggregator portfolio, where you enter into a contract for a monthly revenue payment and they pull together other sites, go out to market and get the best price.

1.4  Other applications:

• Renewable load optimisation (store instead of export)
• EV charging under import capacity constraints
• Grid constraints – can see red areas on your DNO website.  Can help to expand site when no extra KVA capacity is available.
• Load shifting and peak load trimming: charge battery when available capacity and discharge when there’s not

1.5  Case studies:

• Netherlands (Engie): battery takes load from grid and absorbs load from site.  Engie is the in-house aggregator.
• Virtual Power Plant, Wales – 60kW/90kWh.  Proof of concept.  Charging/discharging depending on energy cost forecasting.
• Renewable Load Utilisation (DECC funding – became Connected Energy).  Microgrid balancing; power to EV or manufacturer on site (Lotus).  Batteries look for renewable charge first and demand will use battery first: the grid comes second – all happen automatically / dynamically.
• Dundee City Council: 30kW PV car park canopy.  Power goes purely into batteries (and when full, into the Council building).  Provides load to EV charging.  Payback is about 8 years (6 years without the EV charging costs).  Batteries costs £60-70k; PV costs about £30k.

1.6  We’ve done lots of modelling for local authorities, schools and universities for both behind the meter savings and grid services.  From the Midlands south, the payback is about 5.5 years for a £170k investment (15 year lifetime, with batteries replaced in year 8.  These costs could come down in the near future as more second life batteries come onto the market.

1.7  We are on the LASER battery storage framework (the standstill period has just finished).  Other providers will be on there too, but we might be the only one providing second life batteries.