Mission Critical Power: How To Make Energy Storage Viable For Mission-Critical Sites

New collaboration offers data centres and other critical sites the opportunity to tap into energy storage without compromising on reliability.

Demand side response (DSR) and smart energy grids are playing an increasingly important role in the UK’s energy mix.

Low carbon renewable sources contribute towards more of our power generation. Indeed, May 2019 saw the country go coal-free for more than a week. That’s the longest period on record since the Industrial Revolution.

For mission-critical sites such as data centres, this transition poses a dilemma. Do they jump on the bandwagon and embrace energy storage and its perceived environmental and economic benefits? Or will doing so risk the continuity of their electricity supply? When uptime and availability are the main driving forces, is there any room for compromise.

Riello UPS smart grid graphic
SMART THINKING: How a smart grid-ready UPS fits into a modern energy system

The Age Of ‘Virtual Power Plants’

The new edition of Mission Critical Power magazine explores one possible solution to this conundrum. Riello UPS and energy company RWE are collaborating on a new UPS power supply that combines demand side response capabilities with enhanced system resilience.

It sees a modified UPS fitted with a special rectifier. This enables bi-directional flow of electricity to and from the grid. The power protection device is backed by premium battery blocks with intuitive monitoring systems that make it far easier to detect if a battery may fail or not.

RWE partly covers the cost of the more expensive premium battery. This reduces the initial capital expenditure a data centre must pay for a new UPS.

The energy firm also takes on any associated risks with trading on the energy market. Depending on the project, this can deliver savings of up to £6,000 per MW per year in grid operating costs.

The batteries are split into two elements: emergency backup (only used when there’s an issue with the mains) and commercial (stored energy for DSR mechanisms like Firm Frequency Response).

In the event of a power failure, any electricity remaining in the commercial part can be activated to add to the primary backup to increase overall runtime.

Putting Energy Storage Into Practice

Our partnership with RWE includes a pilot plant we’ve been running at their HQ in Essen, Germany since September last year. Carrying a 100 kW secure load, the project is shortlisted for the annual Datacloud Global Awards.

Plans are for a follow-up UK pilot to go live later this year.

For a site with a typical 1 MW load plus batteries installed to offer 10 minutes autonomy and 1 MWh of frequency response, the benefits for mission-critical sites are clear.

Lower capital and operational costs. And thanks to the mandatory 24/7 battery monitoring, reliability is greatly enhanced compared to a traditional UPS without such capabilities.

Initial Capital CostsConventional UPSRiello UPS & RWE Alternative
Total CAPEX Saving£80,000 (21%)
Operating Costs (Yearly)Conventional UPSRiello UPS & RWE Alternative
UPS Maintenance£4,500£2,200
Remote Monitoring£1,500£800
Total (per year)£6,000£3,000
Total (10 years)£60,000£30,000
Total OPEX Saving£3,000 per year (50%)

*** Please note that all figures and savings are illustrative only. All costs are project dependent ***

Read more about our energy storage partnership with RWE in Mission Critical Power magazine