Elemental Excelerator, a nonprofit investor in climate-tech startups including BlocPower and ChargerHelp, says it’s “doubling down” in the wake of Silicon Valley Bank‘s collapse. Elemental intends to pump $43 million more into climate-tech startups — $13 million of which will be set aside for its twelfth accelerator program, beginning in October. The investor hasn’t secured all of the money yet; it is…