They wouldn't need investors if this worked. Once you build one it can be used to generate energy which is in turn sold for cash. Generate enough cash and you build the second to generate more energy for more cash. Kinda like the alfalfa growing in Catch 22.
With high tech start-up companies the scheme works like this. Develop a concept for a new product then a business plan then an IPO plan. Seek venture capital to perform the R&D for 2-4 years before product is ready. The investors do not care if the product ever workd because they have been guaranteed an IPO BEFORE the product goes to market. They sell their shares often for double or more their purchase price. They make a killing. The company execs make a killing with the IPO.
And still no sales yet (except maybe a few prototypes, but nor necessary)
All of this "killing" is totally dependnet on the amount of pre-IPO hype and publicity that can be generated.
They hire a professional pre-IPO PR firm to handle this.
This type of thing was running rampany during the Clinton years and created the huge bubble that burst. Tons of companies getting huge sums of capital while they have no products or market share.