Years ago, the story I understood was that renewables couldn't scale up fast enough to sufficiently mitigate climate change, and nuclear was the only answer. Recently, I've read that renewables have scaled up much faster than expected.
Does anyone know the current story? Can renewables scale up fast enough? Also, does the availability problem (i.e., renewables not being available when the sun/wind are not) prevent them from having a sufficient impact? I could imagine that, even if renewables weren't always available, their use still could reduce greenhouse gas emissions enough to mitigate climate change sufficiently.
Availability is a problem. Right now we're mainly backing up renewables with fossil plants.
Most people really aren't getting what climate scientists are saying these days, which is that we have to cut emissions drastically in the very near future to avoid disaster. If we exceed +2C, or possibly even +1.5C, positive feedbacks will take the planet several degrees further even with no more emissions from us. Right now we're at +0.8C. Every ton of CO2 we emit takes 30 years to have its full effect on the temperature, considering direct effects alone, so we've got another 30 years of warming locked in already.
+4C or so might not sound like much but judging by geological history, the effects would include an enormous reduction in the amount of food we're able to produce.
Solar photovoltaic has dropped in cost significantly which is awesome for many applications. The problem for an individual or the grid for renewable intermittents is the consistency: the true cost is the cost not just of generation but generation plus storage (or backup).
Batteries have not had the step change in cost vs deliverable, and the question of effective and not carbon intensive recycling of batteries and most e waste remains. If solar is x cents a kWh, must add cost of storage or fossil backup generation to make sense in both terms of cost as well as carbon.
For instance, the expected cost per kWh of the Powerwall is about 35c/kWh which must be added to cost of generation and the maximum amount of time for delivering that power back at peak discharge is only a few hours. Leaves some development still to do for power in the morning after the night, or even for a cloudy day. Solar thermal has run into similar reliability problems as solar photovoltaic.
Does anyone know the current story? Can renewables scale up fast enough? Also, does the availability problem (i.e., renewables not being available when the sun/wind are not) prevent them from having a sufficient impact? I could imagine that, even if renewables weren't always available, their use still could reduce greenhouse gas emissions enough to mitigate climate change sufficiently.