We think it's very effective to spend more. Consider that, globally, only $22 billion in public funds are spent on clean energy R&D annually—this is only 0.02% of World GDP. For comparison, world energy expenditure was 6% of the World's GDP. This means we spend about 300 times as much on energy than on making energy better.

Why is there so little investment in clean energy innovation?

Generally, basic R&D is under-supplied at both the private and public level. There are several theoretical reasons for this:

On a global level, basic clean energy R&D is under-supplied by both governments and the private sector. Why? Because it suffers from the free-rider problem, as all basic R&D and public goods do. Countries and firms can just let others do the basic research and then reap the benefits because knowledge is hard to protect internationally. Private R&D cannot be protected perfectly because patents expire or industry know-how diffuses to other firms and not all rents from investments can be captured. This results in a socially suboptimal investment.

In other words, additional public investment through basic R&D funding and subsidies increase social surplus, because private capital can only capture a fraction of the social surplus pie.
Generally, venture capital and the market neglect capital-intensive, high-risk, high-return, long time-horizon investments.

Clean energy R&D, in particular, is under-supplied because externalities of carbon are not priced adequately, leading to insufficient commercial applications for clean energy R&D.

So, advanced economies should be spending much more on clean energy R&D. This view is shared by a number of academics, international organizations, and members of the private sector, including:

1. Daron Acemoglu, the most cited economic scholar in the recent decade, who argues that optimal climate change policy requires both carbon pricing and subsidies for clean energy research. Clean energy research should be heavily front-loaded to carbon taxation, which can be phased in gradually to minimize switching costs for industry.[19] This argument is not about how high carbon taxes should be in absolute terms or when exactly they should come. It merely suggests that we need to prioritize clean energy R&D, because it would not make much sense to create better clean energy technology later this century. In short, there is good reason to prioritize clean energy R&D.

2. The International Energy Agency notes that public R&D on energy technologies grew at an average rate of only 2% per year in the last 5 years.[20] For that reason, they argue that more spending on public and private clean energy R&D would be productive and is needed.[21]

3. The Breakthrough Energy Coalition,[22] a private sector coalition of billionaires led by Bill Gates, has started a venture to invest in breakthrough energy projects.
According to recent analyses, public energy R&D can productively absorb large amounts of additional funding[23] and should increase 5-fold to be socially optimal. The US R&D budgets should even increase 10-fold.[24]

A 2018 meta-analysis summarized the results of several studies[25] that all asked several experts by how much clean energy prices if clean energy R&D were to increase. The meta-analysis concludes:

"[...] experts largely believe that increased public RD&D investments will result in reductions in future technology costs by 2030, although possibly with diminishing marginal returns. [....] for all technologies, experts see the possibility of breakthroughs that would make the technology cost competitive, envisioning sustained annual rates of cost reduction on the order of 10 percent per year. Moreover, such breakthroughs appear more likely under higher RD&D."[26]

The results from these experts surveys: moving from low to medium or high R&D investment scenarios might decrease clean energy costs by several percent.

You can find all citations and the full report here: https://lets-fund.org/clean-energy