Tesla is ramping up battery production to aid Puerto Rico - but installations costs are reportedly skyrocketing

Tesla CEO Elon Musk said he's making battery production for Puerto Rico a top priority - but installation costs have reportedly been prohibitively expensive for many locals.

Tesla delayed its electric semi-truck reveal in part to focus on ramping up battery production for the storm-ridden island, Musk said Friday.

Tesla has been shipping hundreds of its residential batteries, the Powerwall, to Puerto Rico. This way, residents who already have solar panels installed on their houses can use the batteries to restore power while the electrical grid is still down.

But with so many people in need of power, it's no surprise that demand has far exceeded supply. It certainly doesn't help that some third-party installers are charging excessive premiums, Electrek first reported.

Some locals told Electrek that installers have charged as much as $12,000 for a Powerwall with installation. The $6,200 Powerwall typically costs between $800 and $2,000 to install, according to Tesla's website.

Musk said on Friday that Tesla always charges the same price for a Powerwall and will stop shipping units to installers charging excessive premiums.

He added that the internal Tesla team on Puerto Rico is very small and the company is working to send more experienced installers to train and hire locals.

A Tesla representative declined to comment beyond Musk's statements.

Musk said increasing battery supplies was a top concern after speaking with Puerto Rico Governor Ricardo Rossello, who said he was interested in using Tesla's commercial batteries, the Powerpack, and solar panels to rebuild the island's electrical system. 

Hurricane Maria, a Category 4 storm, knocked out power for the Puerto Rico's 3.5 million residents, and they may not get power again for another six months.

Get the latest Tesla stock price here.