Caldera to crowdfund for investment in its ‘storage boilers’

Industrial heat battery specialist Caldera is crowdfunding for a new phase of fundraising, following a successful round two years ago, where over 1250 people invested in the company.

The Fareham-based company is inviting potential shareholders to register their interest at:

The company, which is targeting large scale applications such as process heat, is expanding fast, with 20 people working on the development of a ‘storage boiler’ and plans to scale the business further in 2024. It says its systems can replace or supplement any industrial or commercial fossil fuel boiler, cutting carbon, and when paired with on-site solar or wind, also cutting costs. For businesses that need process heat they provide the same energy storage benefit as batteries more affordably, and can generate steam, hot water or air.

The company said it is using  £4.3m recently awarded from the government’s  Industrial Fuel Switching Competition to build a large industrial demonstration system at the Fareham factory.

Its storage boiler concept combines a control system which provides smart switching from grid to on-site solar or other low carbon sources; an array of heat cells, each containing a solid core which ranges in temperature from 200 to 500 deg C and is encased in vacuum insulation; and a heat extraction system utilising a closed loop with a small amount of steam running through the cells. A heat exchanger then transfers the energy to water, steam, thermal oil, or air.

Caldera says the main application for every storage boiler is to ‘turn intermittent or variable priced power into 24/7 clean heat’.

As the system is modular the amount of storage, charging and discharging power can be configured as required to a wide variety of industries and site sizes. The company says it recommends using the technology for process heat, but space heating applications are also possible.

Caldera says:

Storage Boilers can provide heat from 0 to 300 deg Celsius. Heat pumps work well up to around 80 deg C and have the advantage of multiplying the energy input. Outputs over 200 deg C are possible but reduce the amount of heat that can be stored, so around 300 deg C is the highest output temperature that should generally be targeted. This range includes most common process heat applications, such as water boiling and 10 bar steam.

Adding energy storage can remedy issues that a site might otherwise have with distribution network connections. Electricity imports can be limited to fit within an existing connection size, avoiding costly upgrades. Wind or solar can be absorbed by the storage boiler, meaning more power generation can be fitted than can be exported.