Using such a system in the USA based on current pricing and above comments makes no sense. It would be interesting to know how many therms of gas it takes to produce 1 KWH of electricity? Then would give us a better idea of the economics of this type of technology. The exhibited plant is also advertized as plugged up to an ancient technology tank water heater. IF the technology were so advanced you would think that they would plug it up to a tankless system? None of which makes any sense.
I'm better with the technical (electrical) than the share price charts so I'll offer a few comments.
1 kWh is by definition 3.6 MJ (megajoules) of energy. In Australia, gas is sold in MJ so that makes calculation easy (gas is sold under different systems of measurement in different countries).
At the claimed 60% efficiency of converting gas to electricity, it would thus require 6 MJ of gas to produce 1 kWh of electricity.
You'd need to check local prices to work out the economics of that but in Australia gas (wholesale or retail) is generally quite a bit cheaper than electricity in the same situation (wholesale, retail) so converting gas into electricity is, on paper at least, profitable on a day to day basis (ignoring capital costs of equipment). It's still viable to build new baseload gas-fired power stations in Australia for this reason.
Main reason for the cheap gas is that Australia is still on the up ramp of gas production with production capacity exceeding domestic consumption and available export (LNG) capacity. That will all change once enough LNG plants or built, production peaks or domestic demand rises - then we'll end up with international gas prices that are higher than typical Australian prices. That situation already exists to some extent in Western Australia but not the other states (noting that there is no gas pipeline between WA and any other state and that WA is Australia's dominant gas producing and LNG exporting state).
As for the water heater, that relates to the means of operation. The heat produced is a by-product of power generation and is produced at a relatively constant rate throughout the day. In rough terms, I'd estimate that about 0.85 kW of heat is extracted which is nothing compared to the typical 40 kW output capacity (from 50 kW gas input at 80% efficiency) of a continuous flow (known as tankless in the US) domestic water heater. Hence producing the hot water slowly and storing it for when it's needed is the only practical option here.
For reference, a typical electric water heater with a tank would have an input of 1 to 6 kW with ratings of 3.6 or 4.8 kW being very common in Australia for tanks connected to off-peak electricity.
It's worth noting that this concept of generating power and having heat as a by-product applies to
all power stations that burn fuel or nuclear. Large (or small) scale coal, oil, gas, wood, nuclear etc plants all produce massive amounts of by-product heat. Only problem is there's not much use for it all in the one location, hence it's generally regarded as waste and disposed of via those huge concrete cooling towers many people commonly associate with power stations.
Only those processes that do not start with heat, such as hydro or wind power, do not produce large amounts of waste heat (though there is still some, it's just not enough to be either useful or a problem to get rid of). Some of the older hydro plants just let the heat into the building and they literally leave the windows open to keep the inside temperature reasonable. But you'd never be able to do that with the huge amounts of heat from coal, nucelar etc.
Even your car engine is much the same. It produces mechanical power with heat as a by-product. You use a small amount of that heat to warm the interior of the vehicle with the rest going to waste.