4 ms·

I think with new(er) GaN(or SiC) DC/DC buck conversion, 380V systems can get up to 98.2%, typically around 94% efficiency now. Edit: And voltage of these type

by booli 3y ago

I think with new(er) GaN(or SiC) DC/DC buck conversion, 380V systems can get up to 98.2%, typically around 94% efficiency now. Edit: And voltage of these type of DC grids are often higher (600V - 1000V, or industrial even up to 1500V), so losses in cables are less.

algo_trader 3y ago
Yes. The original commenter is a bit behind the times. There is also reliability advantages. > new(er) GaN(or SiC) DC/DC buck conversion Can you share guide lines about costs? For comparison, utility scale AC inverters for PV are ~$5-$10/kW
- tomas789 3y ago
  Original commenter might be a bit behind on many things but this is actually my day job. Do you have a source for the reliability claim? There are so many good old transformers deployed around the world. Many of them working for 10s of years without a replacement. I'd be suspicious that a buck converter will have longer MTBF than oil submerged transformer. Also, I don't see why it is mentioned here but NREL estimates the cost of grid scale inverters (for installations of 100 MW) to be 5-10x more than what was mentioned. [1] [1] https://www.nrel.gov/docs/fy22osti/83586.pdf https://www.nrel.gov/docs/fy22osti/83586.pdf
  - algo_trader 3y ago
    > but this is actually my day job. You are probably more knowledgable than me. I am just here for the cake. However, AFAIK the most fault prone components in PV are inverters and (where applicable) transformers. > 5-10x more than what was mentioned. This was my mistake. I started with 5c/W and missed a decimal place. None of this addresses the key issue - you mentioned 10% loss for a simple DC converter, and the next commenter [1] mentioned the newer generation of far superior alternatives. [1] https://news.ycombinator.com/item?id=37260441 https://news.ycombinator.com/item?id=37260441
tomas789 3y ago
AFAIK PC power supplies are actually one of the most efficient power supplies out there so I'll use them as a reference. The Titanium class of power supplies is around 94% efficient at 100% load and 90% at 20% load [1]. On the other hand plain old transformers start at around 95% and can go even higher. Random internet source claims that it can be 98.5% efficient [2]. Of course you cannot run your computer at AC. I had mostly grid-scale equipment in mind. I just wanted to use something relatable as an example. [1] https://www.velocitymicro.com/blog/what-is-psu-efficiency-and-why-is-it-important/ https://www.velocitymicro.com/blog/what-is-psu-efficiency-an... [2] https://www.electricaleasy.com/2014/04/transformer-losses-and-efficiency.html#:~:text=Transformers%20are%20the%20most%20highly,transformer%20by%20using%20output%20%2F%20input https://www.electricaleasy.com/2014/04/transformer-losses-an....

by booli 3y ago

algo_trader 3y ago

Yes. The original commenter is a bit behind the times. There is also reliability advantages. > new(er) GaN(or SiC) DC/DC buck conversion Can you share guide lines about costs? For comparison, utility scale AC inverters for PV are ~$5-$10/kW

tomas789 3y ago
Original commenter might be a bit behind on many things but this is actually my day job. Do you have a source for the reliability claim? There are so many good old transformers deployed around the world. Many of them working for 10s of years without a replacement. I'd be suspicious that a buck converter will have longer MTBF than oil submerged transformer. Also, I don't see why it is mentioned here but NREL estimates the cost of grid scale inverters (for installations of 100 MW) to be 5-10x more than what was mentioned. [1] [1] https://www.nrel.gov/docs/fy22osti/83586.pdf https://www.nrel.gov/docs/fy22osti/83586.pdf
- algo_trader 3y ago
  > but this is actually my day job. You are probably more knowledgable than me. I am just here for the cake. However, AFAIK the most fault prone components in PV are inverters and (where applicable) transformers. > 5-10x more than what was mentioned. This was my mistake. I started with 5c/W and missed a decimal place. None of this addresses the key issue - you mentioned 10% loss for a simple DC converter, and the next commenter [1] mentioned the newer generation of far superior alternatives. [1] https://news.ycombinator.com/item?id=37260441 https://news.ycombinator.com/item?id=37260441

tomas789 3y ago

AFAIK PC power supplies are actually one of the most efficient power supplies out there so I'll use them as a reference. The Titanium class of power supplies is around 94% efficient at 100% load and 90% at 20% load [1]. On the other hand plain old transformers start at around 95% and can go even higher. Random internet source claims that it can be 98.5% efficient [2]. Of course you cannot run your computer at AC. I had mostly grid-scale equipment in mind. I just wanted to use something relatable as an example. [1] https://www.velocitymicro.com/blog/what-is-psu-efficiency-and-why-is-it-important/ https://www.velocitymicro.com/blog/what-is-psu-efficiency-an... [2] https://www.electricaleasy.com/2014/04/transformer-losses-and-efficiency.html#:~:text=Transformers%20are%20the%20most%20highly,transformer%20by%20using%20output%20%2F%20input https://www.electricaleasy.com/2014/04/transformer-losses-an....