Traditionally providing power protection, Uninterruptible Power Supplies (UPS) are increasingly being used as back-up or ‘energy storage’ devices. With renewable energy driving a position in the marketplace, general manager of Riello UPS Robin Koffler discusses the role of UPS as a backup device or ‘storer’ of energy, ready for release to the load when the mains fails
With most organisations now wholly dependent on their data, uninterruptible power supplies (UPS) have become a fundamental part of everyday infrastructure. Traditionally UPS has provided two main benefits, the first being power protection. The UPS manages a variation in electrical power resulting in malfunction of equipment failure. Common power supply problems include surges, spikes, transients, sags, brownouts or electrical line noise.
The second benefit of UPS is battery back-up, where it is used as an alternate power source should there be a complete power failure.
Over the years, IT equipment has developed to become more robust and less sensitive to power supply problems. While the role of UPS as a power protection device is just as important as ever, in an increasing number of instances, UPS are installed primarily as a back-up or ‘energy storage’ device for use should the mains supply fail.
What are the factors in the energy storage market affecting this?
Energy storage technologies such as flywheels, which can store kinetic energy and compressed air storage that can be pumped into underground caverns, are rapidly establishing a place in the retail energy market as their capabilities are becoming better understood by both customers and energy service companies, who are beginning to see them as a useful tool.
UPS and its emerging function as an energy storage device provides a reflection of the wider renewables industry where low-cost energy storage is referred to as the ‘holy grail’. Reliable and affordable energy storage is a pre-requisite for using renewable energy in remote locations, the integration into the electricity system and the development of a future decentralised energy supply system. Energy storage therefore has a pivotal role in the effort to combine a future, sustainable energy supply with the standard of technical services and products we are accustomed to and need.
EU energy policies have clearly identified energy storage technologies as an area to be pursued further, given their potential contribution to energy security and greenhouse gas emissions reductions. Stored electricity can be used to provide the load following reserves necessary to balance and integrate variable renewable sources of energy such as wind and solar.
When wind turbines generate power, this is fed into the grid, reducing the need to run less carbon-friendly power stations. The same can be said for large or even domestic solar PV installations. The problem is that you only ‘get’ electricity when it is windy or the sun shines. This is why energy storage is seen as so important as we look to find ways to store millions of watts of excess electricity for times when the wind doesn’t blow and the sun doesn’t shine.
There are signs this goal could be well within reach. Some technologies that can store sizeable amounts of intermittent power have already been deployed.
One storage approach seems obvious: to improve battery technologies. Today, the vast majority of new rooftop solar photovoltaic panels are connected to the grid, using it as a giant battery, pushing excess power onto the grid when solar panels provide excess power. The building then draws power from the grid when the sun doesn’t shine, with its meter spinning backward and forward with the ebb and flow of power.
UPS already acts as an energy storage device on a smaller scale protecting critical loads when the power fails and in the future we may see UPS evolve even further.
The UPS industry is constantly evolving and exploring ways to make their operation greener to contribute to the wider energy picture. There’s a question of whether some on-site solar or wind generated energy could be used to charge the batteries in a UPS which would provide not only a greener option but potentially a cheaper one too.
The future may also see the ability to discharge a UPS back into the grid when the battery power was not in use and just leave enough time for recharge. And we may see UPS used as a vital tool in the national grid and quite possibly play a part in the smart grid roll out.
What about now?
This is, of course, a long way off but gives a slight indication as to the direction UPS may take in the future. An understanding of what an important part renewable energy will play in the future of the UK electricity supply is needed in the critical power arena. All critical power manufacturers need to make sure their products are as energy efficient as they can possibly be. Not just energy efficient now but lifetime and beyond. They must keep running costs low and design life high, and that even at the end of their working life they can be removed, re-deployed, dismantled and/or recycled easily and efficiently.
Riello UPS has demonstrated this in the expansion of its product range to support emerging technologies such as solar and wind energy, as well as making sure some of our UPS is smart grid ready. We have a partnership with AROS Solar Technology, part of the Riello Elettronica group to offer a range of high-quality solar inverters to the UK market.
We have also invested heavily in developing and introducing products with high efficiency ratings, such as flywheel UPS technology. A flywheel is a mechanical device that rotates at incredible speed, 20,000 – 50,000 rpm in many cases, and produces kinetic energy, which is then stored. It works by accelerating a rotor (using a source of mains electricity) and maintaining the energy in the system as kinetic energy. The amount of power stored in a flywheel is proportional to the square of its rotational speed.
Even remote locations can benefit from energy storage with containerised solutions which is something Riello UPS has released recently in the form of PowerBox, which can be easily deployed and installed whenever needed.
In terms of power protection, UPS play an important role in improving energy efficiency, and manufacturers like Riello UPS have invested heavily in developing and introducing products with high efficiency ratings, as well as finding ways of ensuring the eco credentials of power protection systems.
Work is always being done to develop battery technology further to make it greener and more robust, eliminating the use of fossil fuels completely. The ultimate aim is to develop batteries that last longer, charge quickly and are inexpensive, but is this possible? While we back all development in battery power, the quote from Jeffrey Chamberlain, leader of Argonne’s energy storage initiative, including advanced batteries, sums up the answer to that question. When asked whether battery is going to supersede or replace the internal combustion engine, Chamberlain responded: “That’s never going to happen: not in my lifetime, my children’s lifetime or my children’s children’s lifetime.”¹