While batteries make most of the headlines when it comes to the energy storage requirements of electric cars, the capacitor could be an exciting and viable alternative. Unlike batteries, which store chemical energy and make it available for use as electrical energy, capacitors store energy in the electric field between a pair of conductors. Supercapacitors, or ultracapacitors, are currently being developed which could rival batteries in the amount of energy that they can store. Whether capacitors see use as part of a hybrid drivetrain or as the sole source of electricity for a pure electric vehicle, we expect to see them make a dent in the automotive sector as the future unfolds. Then again, we've been expecting some news on this front for a while (EESTOR, anyone?), so we might have to keep waiting.

Check out Number 3.

ZENN Motor Company has paid $2.5 million for a 3.8 percent equity stake in ultra capacitor developer EEStor. The deal means that ZENN gets an exclusive deal for EEStor's batteries for small and medium sized vehicles. EEStor is going to use the money to fund the next stage of testing of their capacitors by an independent third party lab. If the capacitors meet the requirements laid out in the equity agreement, then ZENN will have the option to invest another $5 million dollars under the same terms as the initial investment.

Related:

• More on EEstor's ultracapacitor - can we believe the hype?
• Quick update on EEStor and ZENN Motors

[Source: ZENN Motor Company]