While many industrialized economies have a lower carbon intensity than a few decades ago, what matters for climate change is not carbon intensity, but total cumulative emissions. Carbon intensity is an often used metric, but it is flawed for achieving climate change goals.

This is what degrowth advocates point out: a relative decoupling between GDP and greenhouse gas emissions can still lead to an increase in total emissions if GDP grows faster than carbon intensity shrinks. Even though there has been a 34% decrease in carbon intensity (CO2e/$) between 1965 and 2015, total emissions increased by 300%. To decrease carbon emissions, we would either need to (a) have absolute and strong decoupling between emissions and GDP and/or (b) reduce society's dependence on GDP to flourish, at least temporarily. The former solution is often called 'ecomodernism', while the latter is 'degrowth' or 'post-growth'. (Background info on decoupling here.)

Obviously, degrowth approaches, too, can have their drawbacks (e.g. lower tax revenues, typically lower tractability). But I would keep away from calling degrowth a "non-starter" and use the scout mindset to explore ideas within it. Personally, I wouldn't support EA going all-in on the degrowth train, but there are probably worthwhile ideas and solutions coming from the degrowth economy that would otherwise be unlikely to get funding, as governments and companies have no incentive to advocate for degrowth. That's worthwhile to explore!

Remember that OP did not argue that EA climate change funding should all go to degrowth approaches, but merely for "further exploration and research as to it's [sic] viability as a funding opportunity". That seems like a fair idea to me.

I don't have a lot to add that hasn't been covered in the answers below. One thing I would add is: regardless of who owns the company, do you think that home batteries is the biggest impact you can make on climate change with your skillsets, or are there perhaps other fields that are working on climate solutions that score higher on importance, tractability and neglectedness. 

You could take a look at the Open Sustainable Technology list for inspiration on how programming can be impactful. Project Drawdown has a great list of impactful climate change interventions. If you have expertise on AI and machine learning, you can also check out Climate Change AI.