Battery storage, smart grid and energy efficiency companies raised over $839m in venture capital funding in the first half of this year.

However, according to a new report from analysts at Mercom Capital, total corporate funding, including venture capital, public market and debt financing, in the six-month period was down, with $2.4bn raised compared to the $2.8bn a year earlier – a 14 per cent decrease year-on-year.

Mercom said this decline was due to lower funding activity in smart grid and energy efficiency sector.

But funding was up in the battery storage sector. Venture capital funding for battery storage firms was $539m – up 12 per cent to the $480m raised in the first half of 2017.

The top five of these deals were $80m raised by Stem; $71m by sonnen; $65m secured by Ionic Materials; Durapower’s $40m; and another $40m raised by Ice Energy.

Meanwhile, venture capital funding for smart grid companies was 56 per cent lower on 2017, standing at $135m compared to last year’s $304m.

The top five smart grid deals were $55m raised by Smart Wires; $27m by Bidgely; $20m secured by Husk Power Systems; Mnubo’s $17m; and $6m raised by Simple Energy.

In the energy efficiency sector, venture capital funding was 32 per cent lower than 2017, at $165m compared to $242m.