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Japan’s rapid switch to PV September 30, 2014

Posted by Maury Markowitz in power grid, solar.
Kagoshima Nanatsujima PV plant

Kagoshima Nanatsujima PV plant

I came across this article mentioning that Japan has installed 11 GWp of renewables in the last two years. That’s not record-setting by any means (the US beats that), but definitely worthy of comment for a couple of  reasons…

Supporters of other solutions to the “energy problem” (assuming for the moment that such a thing exists) always seem mystified by renewables, especially wind and solar. These sources are intermittent, can’t be relied on, and (so they say) cost too much. Wouldn’t you rather have a nice warm reactor that runs 90% of the time, for years?

The answer is “obviously not”, as the world’s energy supply rapidly turns to renewables. When faced with this fact, supports often point their fingers at “stupid environmentalists” or “idiot politicians” as the cause of “the problem”.

But the real reasons for this are simple, plainly obvious, and so far haven’t been mentioned let alone addressed. And that problem is speed. Time is money, they say. Let’s expand the original question a bit and you’ll see what’s going on. Would you rather:

  1. Have a source of power that runs 90% of the time and will be ready in seven years?
  2. Have a source of power that runs 20% of the time and will be ready in three weeks?

What am I talking about? Well, back to those numbers from Japan:

Japan, which has a total population of 127 million, has approved 71,780 MW of renewable energy projects, according to the ministry data. Solar accounts for 96 percent of the approved capacity.

So basically in the last two years they have approved about 70 GWp of PV, and installed 11 of it. To put that in perspective, the entire Japanese nuclear fleet had 52 GWp and took decades to build.

Ask any banker which system he’d rather pony up cash for. Ask anyone at all. A decade-long project assumes time-dimension risk that makes the CAPEX estimates highly unreliable, and that’s the problem. Banks don’t like risk. No one does.

Now where would be a better place for panels than this?

Now where would be a better place for panels than this?

Especially the power companies. In this article, published only today, one finds a common refrain – the power companies pushing back by limiting connection contacts. It also raises questions about the quality of the offers currently on the table, with an especially funny example being someone that wanted to put panels on Mt. Fuji!

On a purely technical note, I found this statement at the bottom interesting:

In addition to capital, GE will supply some of the inverters — marking the debut in Japan of the GE 1 MW Brilliance Solar Inverter, which eliminates the need for an intermediate transformer, resulting in higher conversion efficiency and superior grid performance, according to GE.

Conventional inverters output voltages on the order of 22kV, or similar “intermediate” values. These are then stepped up or down as needed for distribution, because everyone’s distribution network is different. It’s simple enough to use a transformer to step that up to the actual line voltage for transmissions, and a transformer might be somewhere between 95 and 99% efficient.

What they’re talking about here is getting back that 1% by going directly to the grid voltage in the electronics. This is not going to be cheap, but that’s the interesting point – the systems have been squeezed so hard that even limited gains like this are worthwhile. It illustrates just how much effort has been invested in the PV world in the last couple of years – 90% inverters were uncommon 10 years ago, 95% is everywhere today, and now they’re replacing whole chunks of the network to get that last little bit.


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