The energy optimisation company has added Exelon and Total to an investor base already containing General Electric and Iberdrola.

The fund, formed by General Electric, NRG and ConocoPhillips, is set to wind down after a tepid year that mirrored a downturn in the energy technology sector.

The round consisted of a $3m debt portion and a $4m equity portion backed by existing investors Intel and Semtech.

The thermal heating and cooling technology developer boosted its overall funding to more than $85m with a round supported by Rex Healthcare and corporate-backed fund WLR China.

White Deer Energy has acquired the interest previously held by NGP Energy Technology Partners.

Seeo secured $17m in a round that will support commercialisation of its lithium polymer batteries for use in electric vehicles.

The pre-paid solar company has now raised $23m in total this year after securing a second investment from solar installer SolarCity.

Renewable Energy Group has paid $20.9m for a 69% stake in the biodiesel company and intends to acquire it fully in the next few weeks.