1. Time to make minor updates to my annual “opinions on #solar” thread.
If you like these, you’ll like my 2019 book, Solar Power Finance Without the Jargon. Five stars on Amazon, apparently “entertaining” and writer knows her stuff”. Also available here: https://tinyurl.com/y6lc3ohl 

2. Solar Power Finance Without the Jargon is the book I should have read before seeking a job in renewables, from the perspective of having worked in this for 14 years.

Link to 2019 thread. 2018 and 2017 are linked so you can see what I got wrong. https://tinyurl.com/y56zx5qc 

3. To the opinions! Solar manufacturing is still a terrible business to be in, though 2020 is better than many years. Competition is vicious and the newest factories have the best technology. Older manufacturers carry heavy debt for factories rapidly becoming obsolete.

4. Crystalline silicon technology is good enough and is still reducing cost significantly, for example diamond wire saws went from new to 100% of the wafer slicing market from 2016 to 2018. Multicrystalline silicon has lost to mono, and for utility-scale, bifacial is taking over.

5. Solar is now the cheapest source of bulk electricity in most sunny countries. We don’t need a technology breakthrough, or subsidies, in solar to achieve massive adoption. Mostly, solar developers just need a grid connection and/or permission to sell electricity.

6. Solar’s cheap but it still costs money. Auction bids below $25/MWh do not reflect the full cost of generation, eg Portugal’s 11 euro/MWh 2020 auction price is a flutter on the long term value of the grid connection. Middle East headlines are opaque internal transfer prices.

7. Grid connections are now the gold dust for the solar (and wind) project development business. To optimize use, we’ll see solar & wind farms with capacity much larger than the grid connection, some with batteries.

8. For this reason, solar curtailment is a feature not a bug. Solar’s probably the easiest source of generation to curtail quickly, so can really contribute to grid stability. And sometimes curtailment is a price worth paying for using a grid connection more fully.

9. Countries that have built little solar to date are not losing to high-solar countries; they waited for a bargain on price and can now hold an auction to find out how little a solar developer is willing to build it for. These first auctions are getting bigger.

10. In 2017, my analysis team covered 42 countries which were significant solar markets doing more than 50MW/year. Now we cover 125 and keep finding ones we’ve missed. It’s a bit of a pain, honestly, but quite exciting.

11. Good solar companies don’t need to pitch the enviro-social of solar in general. They have a few meaningful differentiators (above-average recycling efforts, renewable energy purchase plans) but mostly they differentiate on executing solar well, ie profitably.

12. I refuse to get excited about perovskites until a perovskite company can disclose a partnership with a named major module manufacturer.

(This was my opinion in 2018. It is my opinion still).

13. Floating solar is a thing, but it’s not a new tech. It’s solar onna boat.

14. Agrivoltaics, likewise, is solar onna field.

PV only has synergies with *some* agriculture. Competition for light and restricted mechanical access to crops are often problems. Existing Chinese agrivoltaics are largely PV subsidizing bad farming.

15. Many current household PV systems are designed suboptimally and may not make economic sense or even perform well. Also, most countries will move to paying a pittance for solar exports, so self-consumption rate is becoming the most important financial parameter for rooftop PV.

16. To financially assess a proposed rooftop solar system, you will need at least a year’s data on hourly electricity consumption to estimate selfconsumption. Also, get it built when you have scaffolding up for something else, scaffolding is expensive.

17. Rooftop solar mandates on new construction (like California's) are a good idea. There will never be a better time in the roof's life to add solar than when workers are already on the roof, now the kit is so cheap.

18. There’s more innovation now in system design than in module tech (though some there, eg multi busbars, bigger wafers). East-west orientations use less land and give flatter output profiles, costing ~1 percentage point of capacity factor, than equator-facing systems.

19. Very few people who are not solar project financiers understand tax treatment for solar projects (I don’t) and it’s important enough to make most calculated LCOEs irrelevant to auction prices.

20. Solar thermal tower and heliostat designs are still not working well, although parabolic trough solar thermal has brought down costs more than expected.

We may even end up using molten salt for multi-day and seasonal storage... but heat it with PV.

21. Utility-scale batteries are going to be a massive thing everywhere, both co-located with solar and wind to use a grid connection, and just embedded in the grid. However they’re not going to solve seasonal demand-supply mismatches as the utilization would be too low.

22. Hydrogen is going to be a thing, but not for transport and probably not for seasonal power storage – exactly. Using renewables when they’re plentiful to make H2, then using the H2 to make steel or fertilizer, looks quite promising.

23. Nuclear is safer than coal and climate change, and better than gas unless the gas plants are running very rarely. Batteries might help with the unfavourable ramping economics of nuclear (you *can* turn nuclear plants up and down, but you really don’t want to).

24. We’re finally getting serious about net zero carbon, as of 2020. Whew. Getting that last 10-30% of carbon out will be hard, and require some expensive solutions, but now we have the tech and knowhow to get to 70-90% at reasonable cost.

25. “We” who are finally getting serious about net zero carbon mainly means governments and large companies. I’m pretty sure the general public has little idea how much progress has been made. Tell people at parties that Germany’s at 48% renewables!

26. …It would still really help if rich people would stop pissing away carbon for no reason.

27. Solar is a major part of decarbonizing electricity, but probably not more than 50% worldwide, so we need something else too. Transport will go electric but also we really need to sort out agriculture, shipping and aviation somehow for a sustainably habitable planet.

28. While moving to a circular economy with 100% recycling rates is essential in the long run, it’s not a challenge for PV in particular; few PV panels have been recycled to date only because the vast majority are still in use. It can be done.

29. Solar plant operation and maintenance in desert environments will prove more challenging than PV project stakeholders currently expect.

Also, climate risk from hurricanes, hailstorms, fire and floods is on the rise for solar as for everything else.

30. Traded electricity wholesale markets are the worst way of deciding how to dispatch energy resources, except for all the others that have been tried.

31. Many solar project developers complaining their problem is 'finance' are being disingenuous. Their problem is, their project is rubbish and they cannot convince anyone otherwise.

(This may not just be a solar thing).

32. Building-integrated PV products are usually attempts to sell bad solar products for premium prices to gullible aesthetes and architects.

(This has been my opinion since 2017. My colleagues Yali and Xiaoting plan some BNEF research in December 2020 to see if they agree).

33. Job creation from solar will be less than solar advocates forecast. Relatedly, solar cost will be lower than solar advocates currently forecast.

Being a lot of work is not intrinsically a good thing for a source of power.

34. The whole “only an overall growing economy can support a growing renewables industry” idea needs to die. Renewables industry growth *is* economic growth, and jobs, and nobody said economic growth needed to be homogenous.

Renewables has been resilient to Covid-19 so far.

35. Offgrid solar is driven more by people wanting TVs than by people wanting their kids to have light to do homework. And that’s absolutely fine.

Minigrids, microgrids, and solar home systems with batteries are bringing reliable electricity to the whole world. It's happening.

36. Commercial and residential power pricing structures are going to get more complicated to reflect cheap midday solar. The main role of smart home technology is to take advantage of this. It's not currently doing it very well.

37. There is enough land for lots of solar. There are enough golf courses in the U.S. for about 370GW, ffs.

38. If you’re recording PV capacity and only have room for one figure, record MW(DC). It will tell you more about what the project will produce and what it will cost than MW(AC), which is just the size of the wire.

I will die on this hill.

39. Anyone buying a new internal combustion car now is pretty silly. EVs aren’t the answer to everything – especially congestion of cities – but they do use much less energy and, with flexibility, can support the grid.

Sorry I can't respond to all comments/questions. I needed to pretend to be a lion and chase my two-year-old round the village.