Thousands of citizens have joined pro-solar groups in slamming the Spanish government for attempting to stymie residential energy storage prospects.

Earlier this month, the Spanish Ministry of Energy proposed legislation that would tax owners of solar-plus storage systems $10 per kilowatt of capacity. The proposal has upset many people in the country.

The energy ministry website set up to collect comments on the proposed law crashed after more than 100,000 petition signatures and 34,000 formal objections had been sent in. Two days after the closing date for comments, an Avaaz petition to kill the law had surpassed 180,000 signatures and was continuing to grow.

A separate petition asking for the resignation of José Manuel Soria, the minister of industry, energy and tourism, had gathered 153,000 signatures.

Lawyers for Spain’s renewable energy sector said they hoped the email outage would force the government to extend the standard 15-day consultation period.

“We are going to ask them to extend the period for the same number of hours that the system has been down,” said Daniel Pérez, legal counsel for the renewables-focused pressure group Platform for a New Energy Model, in press reports. “There are organizations that still have not been able to send in their objections to the text, and if you have a public consultation period then you are legally obliged to respect it.”

Calculations from opponents show the law would increase the payback time for residential solar, which is already at grid parity in many parts of Spain, to 31 years. The penalties for adding battery storage are even higher.

This idea is hotly contested in other markets where utilities claim solar system owners aren't paying enough for grid services. In practice, many studies find that net metering users are paying their fair share.  

In Spain, Pérez told GTM: “200 megawatts of self-consumption will reduce [electricity system] revenues by €21 million [$23 million], which is 0.05 percent of the cost of the system.”

Nevertheless, the government appears convinced that self-consumption could imperil the Spanish grid, which so far seems to be coping fine with one of the highest renewable energy penetration rates in the world.

“In the case of a self-consumer connected to the grid, who is not paying for transport and distribution nor for the costs of services that other consumers pay for, those who are not in the self-consumption system will be financing the self-consumer,” wrote the government.

Piet Holtrop, senior partner at Pérez’s Barcelona-based law firm, responded: “The logic of the argument is that if you have simple self-consumption, you only abuse the grid a little bit, but if you use batteries you are more unsocial so you have to pay even more for it. It is a very wicked logic.”

For Holtrop and others, the law was a result of behind-the-scenes influence from the big five power companies. “The impact of self-consumption has been exaggerated by the utilities,” Pérez said.

Worries about cost-shifting are readily accepted across Spain because senior politicians have traditionally occupied well-paid jobs in the utility sector after leaving office.

The right-wing People’s Party (PP) currently has an absolute majority in parliament, so could in theory pass the self-consumption law even in the face of major public opposition.

However, this is an election year in Spain, and the PP’s credibility has been badly eroded during its last three and a half years in power. The party can't afford to anger voters in the run-up to elections at the end of the year. 

The PP’s previous self-consumption proposal, tabled in 2013, was credited with halting Spain’s distributed generation market, even though it was never passed.

Given the need to address the outcome of the public consultation, this new law could easily take five or six months to wend its way through Spain’s legal system. That would give the government plenty of time to decide whether to push the law through before or after the general election. 

However, the threat of the law is already having an influence. Already, said Holtrop, "a lot of people think self-consumption is forbidden in Spain.”