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Comment by rogerthat_au | Hacker News Reader

I run a startup (www.de.energy) that opens up solar as an asset class and funds solar commercial and industrial projects in India and Africa. The last project we funded was for 31,500 INR per kW ($425) and we are currently about to fund a few projects at $364/kW for Tier 1 equipment. This is more expensive than utility scale projects. The estimates in the article are what we are seeing on the ground.

Yes, it is accurate that solar can't supply more than 30-40% of the energy mix. But we are still far from reaching that level of supply in the developing world and faster the cost reduces, the better it'll be for continued deployment en masse. Battery innovation as well as other tech will continue to improve the amount of solar in the energy mix.

Edit: You may also find this helpful - https://de.energy/blog/solars-future-is-insanely-cheap-2020-...

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I’ve had this question for a long while but no one to ask it to. You might have the expertise required to answer it.

When I see new solar projects that have tendered absurdly low prices, are the bidders bidding with today’s solar prices or are they betting that solar prices will fall further, allowing them to eventually make a profit? For example Adani solar won a contract to supply energy at INR 3 or $0.05 per kwh. Is that the price of building and operating a solar in 2022 or is it the price that the winning bidder hopes it’ll be in 2024 when they’re building the second and third phases of their contract?

Your question goes to the core of what we do. Cost of solar on today's price is already really low and the calculation is being done on prices today. Keep in mind per kW yield of solar in India is very different from in the US or further north.

For example, at a cost of 30,000 INR/kW ($405), and a bid price of INR 3, assuming yield of 4.25 kWHr/day per kilowatt, we are looking at an IRR of 10.5% over 20 years. Now add long-term debt to the mix and we are upwards of 12%. Solar doesn't have any moving parts and this assumes operations and maintenance at 15%. If the cost squeezes further by 2024 - the IRR is even more attractive.

Goldman, Walburg, Pension funds, etc are deploying billions in solar for this reason - IRR upwards of 10% over 20-25 years with low risk. That's why we started this business too :)

Yeah it’s a great business to be in. As long as the climate doesn’t change, you’ll be pumping out electricity from a plant at an unbeatable price - since there’s no input apart from maintenance costs. How long do solar panels last before you need to replace them though?

Since you’re so on well informed about this here’s another question. I notice that battery prices are roughly halving every 3 years. At what point does it become cheaper to attach batteries to Indian solar plants than it is to operate coal powered plants?

- How long do solar panels last before you need to replace them though?

A lot of them offer warranties for 20-25 years. Most tier 1 panels are expected to last 25-30 years.

- I notice that battery prices are roughly halving every 3 years. At what point does it become cheaper to attach batteries to Indian solar plants than it is to operate coal powered plants?

At a grid level this is a complex question that I'm not completely qualified to answer because it goes into the larger question of energy mix and energy security. At a factory or building level, we are not that far - we're already offering monthly packages (in terms of cost) which amounts to 10-15c/unit of a blended rate (solar + battery). The min it breaches 8c/kWHr blended rate, this can become more permanent. I'm speculating but some of what I've seen in Li-ion and ESS flow costs we may be two years or less out.

What is the best storage for solar? Batteries, molten salt or pumped hydro?

Is anyone using excess solar energy for desalination plus pumped hydro?

We've only used Li-ion or led acid so far. Li-ion is much better long-term for a number of reasons. We like the idea of ESS flow, but haven't had a chance to use it yet.

No experience w/ solar for desalination or hydro as its outside our focus right now.

    solar can't supply more than 30-40%
    of the energy mix

With enough batteries, why not?

I meant solar on its own.

Solar + battery is where the future of solar is, but the economics of batteries don't work yet relative to grid electricity price in the developing world. So far we've deployed solar+battery in petrol pumps and a few off-grid locations. In the markets where we operate, on grid, it is economically not an option yet.

This is demonstrably false. Batteries and solar are already cost competitive.

https://www.bloomberg.com/news/articles/2018-09-17/solar-wit...

https://www.utilitydive.com/news/new-mexico-approves-100-ren...

Bruh did you miss the part where OP said “developing world”? They’re talking about projects in India, where the grid looks very different from the US grid.

https://energy.economictimes.indiatimes.com/news/renewable/i...

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