Elon Musk is such a good salesman that, despite formidable and blindingly obvious problems, he has managed to convince everyone that batteries and electric vehicles will fix all our energy and supposed pollution problems.

A man who runs an electric car manufacturing company with a share price bid up so high by investors that, at the time of writing, its market capitalisation is comparable to that of General Motors, despite having less than one per cent of the production volume, has to be a good salesman. But Musk’s stand out skill is in extracting largesse from governments around the world.

An indication of his ability to do this is Musk’s Tesla Motors and French wind farm developer Neoen winning a South Australian government tender to build a battery capable of supplying up to 100 megawatts for an hour and 18 minutes. The media was so busy reporting sound bites from Musk that the project was part of the energy future, details such as how much the project would cost the taxpayer were not thought worth mentioning.

About all that taxpayers had to go on in finding out just how much of their money the South Australian government is spending is a chance comment by Musk that if his company does not fill a previous pledge by him that the battery will be built in 100 days of agreeing on a grid connection or it’s free, then he would be out of pocket by $50 million. Another, unsourced estimate given in a list, is that the project will cost about $66 million. The financial details of the agreement are otherwise confidential – a point mentioned in passing in the occasional story.

There was no cost comparison between this battery project and steps the SA government has already taken to stabilise its grid after previous disasters, including keeping 200 megawatts of diesel power on standby, and putting the 239 MW Pelican Point gas plant back in service – power sources that will not go flat after little more than an hour. Nothing was said about how a battery might compare with a pumped hydro project for storing energy, or about the carbon life cycle of the lithium ion battery, which has been the subject of some discussion.

Musk-Neoen’s battery and another, possibly larger battery to be built by the Lyon Group next to a solar farm also in South Australia, are far larger than battery projects announced to date in the US and Europe, and may take some of the edge off price swings in a state with a lot of renewable energy. But if the state government was really interested in smoothing out price peaks they could have permitted an entrepreneur to buy a used 200 megawatt diesel generator which this author saw offered on Alibaba for $US25 million, and sell the output from that onto the grid when prices spike during summer.

Instead, everyone seems entranced by Musk’s grand visions for the electricity and car industry, which include electric cars sweeping away petrol engine vehicles – a vision which also does not stand up to a hard-eyed comparison of cost and convenience to the consumer. The many enthusiastic proponents of EVs, for example, point to sales successes in various countries as proof of the car’s acceptance by consumers. A closer look shows that the success is due to government subsidies.

This point was starkly illustrated in Denmark. In 2015, Danish consumers bought nearly 5,740 of the Tesla S but in 2016 when the government announced it would end a generous tax exemption for electric cars (petrol driven cars are taxed 180 per cent tax of their price) sales collapsed to just 176 units in 2016. In China, sales of new energy vehicles, which include electric and hybrid cars, plunged 74 per cent in January after the government decided to cut subsidies.

EVs remain expensive and so not the first choice of consumers but will the Tesla 3, priced at $US35,000 ($A46,000) not counting any taxes or subsidies, change that? That price tag is certainly more attractive than the Tesla S ($150,000 plus for a used model in Australia), but still double the price of a humble but reliable Toyota Corolla which can be refuelled in a few minutes, cheaply in any country town.

Just as government changes to the rules have resulted in enormous batteries somehow becoming desirable, more rule changes may force consumers into electrics or hybrids. In mid-July, the Australian government released a proposed emission standard that would stop the sales of all the popular cheap cars, in an effort to meet the Paris climate change targets. Volvo certainly seems to be anticipating a market change by declaring that any future models it releases will be electric or hybrids. However, following Volvo’s announcement analysts were quick to point out that the car maker will still be making petrol cars for many years, until existing models are changed or updated. They also pointed out that sales of petrol hungry SUVs and pick up trucks have surged in the US, in part thanks to cheap petrol.

Whatever happens in either the automotive or electricity markets, Musk’s companies will be there and governments will be subsidising their activities. As the Los Angeles Times reported in July, the state of New York is spending $750 million to build a solar panel-making plant for Musk’s company SolarCity (home solar systems) which the company will lease for $1 a year and not pay property taxes for a decade. The company, which like Tesla has yet to turn a profit, also received $US497.5 million in direct grants from the US Treasury among other assistance. Tesla’s main plant for assembling the lithium ion batteries for its cars is literally in the middle of the Nevada desert because that American state won a bidding war for the factory, by promising the equivalent of $US1.3 billion in foregone taxes, cash grants and land.

The Australian federal and state governments may not yet have handed Musk lavish grants as American state and federal governments have, but the lack of disclosure and public scrutiny of the battery deal is an ominous sign of the future.