Fullscreen User Comments
Share on Twitter Share on Facebook Share on LInkedIn Share on GooglePlus






Who needs batteries when unlimited and universal power is just a microwave or two away?

Solar Flare

© Flickr/cc-licence/NASA Goddard Space Flight Center

  • The latest “moonshot” idea harks back to the 1960s
  • Orbiting arrays of solar panels to collect the sun’s energy
  • Microwave transmission back to devices on Earth
  • Is this what will power telecoms in a post-5G world?

As the TelecomTV team starts to unwind for the Easter break, and the weather turns unpleasant yet again, it’s time to use the four-day weekend to ponder some of the big questions that are troubling us. Top of the list this year is power.

Battery technology has, rather annoyingly, lagged the development of devices and networks. Yes, we are getting better at making what we have got (or what we can physically store in a small space) go further and last longer; we are become slightly more efficient. Yet demand continues to increase – not just with smartphones and IoT devices, but the automobile sector is also muscling into this space with a frenzied focus on electric vehicles. In fact, just yesterday it was revealed that UK-based Dyson (famous for its cyclone vacuum cleaner technology) has received government funding to create a new battery-powered vehicle, leveraging its $90m acquisition last year of Sakti3.

Yet batteries only store energy, they don’t generate it. Creating energy is an expensive business and is still predominantly a centralised model that involves an equally expensive distribution system. What if there was a way to not only create and distribute energy at a lower cost, but also to do away with the need for long-life batteries?

Not surprisingly, a plan is afoot. Yes, it’s something of a “moonshot” still, but thanks to the high profile side projects of dotcom billionaires, moonshots are now all the rage.

The idea is to create a solar array that orbits the earth, collecting the unlimited energy produced by the sun, free from the limiting effects of our atmosphere and weather (which can cause performance to drop by up to a factor of 20). The clever part is to use microwaves to transmit this energy back to Earth, and microwaves are for less prone to atmospheric obstacles – pick the right frequency and you can transmit 100 per cent of your signal.

An idea whose time has finally come?

It’s not a new idea; it was first discussed back in the late 1960s, and some initial US research work was conduced during the fuel crisis of the mid-1970s. But it’s always proven to be a prohibitively expensive way of producing energy. Thankfully, innovation has moved on a pace since then, and advances in technology – coupled with the ever-looming threat of fossil fuels and climate change – means that the idea is back in vogue.

As well as research projects underway by the US government (mainly through their Naval Research Lab), Russia, China and Japan are also experimenting. In fact, Japan has pledged to commence orbital tests sometime in the 2020s, with a fully operational Death Star solar array online in the 2030s. The Death Star reference is not so far-fetched, unfortunately, as we are already seeing alarmist reports of how such technology could be weaponised. Yes, if a laser was being used as the delivery mechanism; not so much with microwaves… And whilst we are on the subject, experts assure us that, no, it won’t kill birds, it won’t destroy aircraft, and it won’t make the weather any worse than it is already.

But whilst solar panels are becoming more efficient, with space-based cells reportedly seeing efficiency rates of 30 per cent now, it’s not the biggest problem. Cell technology will improve and become more efficient, and arrays of mirrors can be used to increase the volume of light collected, but the main issue is transporting all of that equipment up into orbit in the first place.

The physics behind solid fuel rocket technology is such that it will remain a vastly expensive business for the foreseeable future – it’s not suddenly going to improve (in order to break into orbit, you have to reach a specific velocity, and you have to carry your fuel with you, which adds to the weight and therefore increases the fuel quantity needed. And so on…). Space elevators could be the next thing, but it require another dotcom billionaire to finance the development of a material that is way stronger than we have today, if it is to support its own weight over distances of 100,000km or more.

Until then, we’ll have to think creatively. If we can’t reduce the cost of rocket launches that much, then we’ll have to reduce the payload size to minimise weight and the number of launches. It costs about $22,000 per kg to carry a payload into space, so for a fully-sized orbital array, capable of generating 10 gigawatts of power (although the first designs will likely generate just 1 gigawatt), you could be looking at anything from $10 billion to $100 billion or more. Compare that to a new nuclear power station, using proven “clean” technology, that costs about $6 billion.

Disrupting the power distribution and storage model

But go further. What if we are able to solve the payload cost problem and construct economically viable solar arrays that can distribute sufficiently high amounts of energy via microwave? Would it not then be sensible to throw out the idea of central land-based power storage and redistribution plants, and instead “beam” this energy direct to all devices across the planet? With almost 24-hour coverage across the globe, and no performance losses due to weather conditions, then you have power on tap – no need for battery-based storage. What will that do to our connected world and the proliferation of IoT?

For the moment, this is all hugely speculative. But then again, so was the idea of reusable spacecraft, tourist trips into space, balloon-based WiFi, and autonomous electric cars. By 2025 we’ll have decent 5G deployment around the globe and widespread IoT. Move that on another decade and the number of powered, connected devices of all shapes and sizes will only get larger. So what are the chances that we’ll start to see microwave-based power from orbiting solar arrays being used by 2035? Probably not such a moonshot after all.


[TelecomTV will resume its daily analysis from Tuesday]

Join The Discussion

x By using this website you are consenting to the use of cookies. More information is available in our cookie policy. OK