Battery-maker Redflow (ASX:RFX) is launching a demo battery in China, a country that is strongly endorsing the kind of battery tech the small ASX company is building.

It was the bounce Redflow desperately needed for its share price, launching it 51 per cent on Friday morning to a high of 5.9c.

Redflow is partnering with local company ZbestPower, providing 10 of its ZBM2 zinc-bromine flow batteries from early June for a six month demonstration of a 100 kilowatt hour (KWh) battery at a smart grid project in Qinghai province.

To put that in context, the big Tesla battery in South Australia — the largest grid-scale battery in the world — can handle 129 megawatt hours (MWh).

But the Telsa battery is lithium-ion based, a chemistry known for being able to ramp up and down very quickly hence why it’s used in vehicles.

Redflow makes flow batteries, which tend to be longer lasting and require little maintenance but are also slower to discharge and recharge.

There are two main kinds of flow battery chemistries, vanadium-redox which a number of companies on the ASX use, and zinc-bromine which is what Redflow uses.

In China, Rongke Power in Dalian province is building the largest battery in the world, an 800MWh vanadium redox flow battery, while in Hebei province Pu Neng Energy is building a 500MWh version.

More energy news:

Tilt Renewables (ASX:TLT) has completed a 20-year power offtake deal with Genesis in New Zealand, but they haven’t said how much it’s worth to them.

The deal means Tilt can now go ahead and build the 130 megawatt (MW) Waverley Wind Farm in South Taranaki.

Tilt has eight operational wind farms in Australia and New Zealand, four wind and solar farms in development in Australia, and six more wind farms across both farms at various stages in the development pipeline.

“The Waverley Wind Farm comes at a price that is competitive with other forms of baseload electricity, which is particularly important as we meet demand from the transport and industrial heating sectors looking to electrify in the coming years,” said Genesis chief Marc England, adding that it won’t “materially” impact the cost of power in New Zealand.

The final investment decision and start of construction will be within the next six to nine months.

Tilt’s crown jewel, and the project that attracted two bidders, is the 336MW Dundonnell Wind Farm in Victoria which is now under construction.

Tilt went through a bruising fight last year with major shareholders Infratil (ASX:IFT) and Mercury NZ (ASX:MCY) which had offered shareholders $2.30 a share for the company.

Tilt convinced its investors this vastly undervalued its current assets and potential with the flagship 336 MW Dundonnell Wind Farm, for which it successfully won state-backing under the Victorian Renewable Energy Auction Scheme.