Our post-industrial world is now expe riencing one of history’s greatest technological revolutions. Renewable energy is plunging in price, and the Cape and Islands are center stage. Unfortunately, we are also in a whirlwind of nuclear disaster that needs to end as soon as possible. Never has the demand to shut atomic reactors been so imminent — and so possible.

We’ll discuss all this at a free and open gathering at 7 p.m. Wednesday, July 30, at the Simon Gallery, 54 Main street in Vineyard Haven.

First the good news: Throughout the planet the price of photovoltaic cells (which convert sunlight to electricity) is dropping extremely fast.

Much of the impetus is from China, where mass production has taken deep root. Unfortunately, much of this comes at the expense of Chinese workers, who are laboring under terrible conditions for far too little money. Rampant pollution from the process also threatens China’s already beleaguered environment.

All this needs to change.

But the Chinese have clearly determined to corner as much of the PV market as they can. They have also begun to install collectors on individual homes in various parts of their own countryside. This will further drive down electric prices and will also cut into the huge quantities of greenhouse gases being emitted by China’s overlarge fleet of coal-fired power plants. Worldwide they have lowered the prices of PV to where it is cheaper vitally everywhere now to install solar as opposed to new fossil or nuclear generators.

Likewise, wind power continues to become ever-more efficient. Large-scale wind farms are proving extremely profitable throughout the U.S., Europe and Asia, and growing more so every day, especially on the windy Cape.

Green power is specially impactful in Germany, where a combination of wind, solar, efficiency and conservation is being used to change the entire energy system. This energiewend means a total shift from fossil and nuclear fuels to a green-based supply system that will make Germany completely green and energy self-sufficient. The timetable for this to happen focusses on the 2020s, and there have been some expected glitches. But overall, Germany’s transition to a totally green energy economy is ahead of schedule and under budget, as has proven true of much of the rest of the world’s experience with wind and solar.

Other renewable forms of energy, such as ocean thermal, geothermal, wave energy and tidal energy are also moving ahead rapidly. Bio-fuels also have their place, especially as the repeal of marijuana prohibition moves forward, bringing with it the legalization of hemp, one of our best potential plant sources of industrial-scale energy.

All this, of course, plays out importantly in the Cape and Islands. Wind is spreading rapidly through the region, along with PV. The region has ample natural resources for a wide range of renewables, and should be making the most of it in years to come.

But all this comes with the tragic backdrop of nuclear power plants that have grown increasingly dangerous. Islanders generally worry most about Pilgrim, because it’s also in Massachusetts. But the Cape and Vineyard are also threatened by upwind reactors in Connecticut, New York, New Jersey and elsewhere throughout the Northeast.

All these dangerous, decrepit reactors are aging ungracefully, with increasing peril to us all. Given how these old nukes are decaying, it may not take an earthquake/tsunami to cause the next radioactive disaster. It’s not reassuring to know that Pilgrim is a clone of Fukushima Unit One, which exploded after March 11, 2011.

Even worse is the reality that childhood thyroid cancer and abnormality rates around Fukushima are now 40 times normal. And that studies from Germany and elsewhere show that disease rates around reactors that operate even without major accidents are distressingly, abnormally high.

Thankfully, we now have the technology to bring us to Solartopia, a totally green-powered Earth. It’s happening rapidly worldwide.

For the health, ecological and economic future of us all, let’s push hard now to follow in Germany’s footsteps and make our region, our nation and our civilization into a truly green-powered reality.

Harvey Wasserman wrote Solartopia! Our Green-Powered Earth (introduced by Robert F. Kennedy Jr.) and edits nukefree.org. He will speak at 7 p.m. on Wednesday, July 30, at the Simon Gallery in Vineyard Haven. The talk is free and open to the public.