Renewable Technologies on the Cusp

by Henry Kaplan | Jul 31, 2014 |


(By Aioannides [GFDL or CC-BY-SA-3.0], via Wikimedia Commons)

You probably remember a time when the thought of widespread solar and wind energy seemed far from reality. Interesting or intriguing, maybe, but not practical, and certainly not inevitable. But in recent years, solar panels and wind turbines have sprouted across rooftops and hilltops. They’re not our primary sources of power, but they’re in the mix. They’ve joined the big leagues.

So what up-and-coming technologies will join them next? What else will make the leap from promising technology to successful industry?

It’s a hard question to answer. There is no shortage of breathless anticipation for experimental technologies. Every day, we see the news stories. (Scientists can make fuel from CO2 waste!) But there’s a big difference between a technology that’s proven in a lab, and a technology that can succeed in the energy industry. A breakout technology needs support from the industry and the government, and it needs to be economical.

Not many are there yet. But a few technologies might be on the cusp. They have the support, the interest from researchers and developers, and the demand from the industry. They just need a few missing pieces to fall in place.

Large-Scale Batteries

As solar panels spread across rooftops and backyards, one troublesome issue keeps popping up. Solar panels don’t always provide the right amount of energy at the right time. They receive most of their sun in the afternoon, when people aren’t home. Most households, however, need the most electricity in the evenings, when they turn on the lights, the computer, the television, the AC, the kitchen appliances, and other devices.

Right now, we get around this issue by hooking those solar panels into the wider grid, sending that energy to nearby homes and businesses that might need it. But large concentrations of solar panels can cause trouble for the utilities. They can’t easily power up and down power plants at a moment’s notice, so it’s hard for them to compensate for the fits and starts of solar energy.

Everyone has the same solution in mind: large-scale batteries, charged up by solar power during the day, providing that power during the evening and night. At the Intersolar North America conference, attendees focused on batteries more than anything else.

We have the technology to make these batteries, and we have the demand. We’re just waiting for the first business to make it truly succeed. And many are fighting to be that first business. Elon Musk stands particularly tall in that field. He’s been hyping his plans for a huge battery factory for a while. (New details on the plans for that factory just hit the news today.) He sees new battery technology as a key part of both SolarCity, his solar business, and Tesla, his electric car business.

But Musk is far from the only figure trying to win this fight. They all think that large-scale batteries could breakthrough, and they all want to be there when they do.

Concentrated Solar

Here’s another technology that can chip away at the problem of solar variability. Unlike photovoltaic solar panels, concentrated solar systems focus sunlight on a central point and use the heat it generates to create electricity. As an added bonus, that thermal energy can be used to heat a central mass, which can store that heat and produce electricity even after the sun goes down.

In essence, this system acts as its own short-term battery, storing solar energy for hours.

Concentrated solar technology works – it’s been built and used on a large scale. But it struggles to compete with solar panels, which can be produced and installed much more cheaply. After contributing to the Ivanpah concentrated solar plant, Google, originally a big supporter of concentrated solar, backed off. They’ve turned to solar panels instead. And so have many others.

But one major player hasn’t slowed its support: the U.S. government. In the last year, the Department of Energy has renewed their push for concentrated solar energy. Why the support? For one thing, the NREL found that the energy concentrated solar plants produce is higher-value energy than energy from solar panels, in large part because it produces energy in the evening, when energy is in greater demand.

Compared to solar panels, concentrated solar plants offer both great advantages and great disadvantages. Due to their greater up-front costs, developers have been slower to adopt this technology. But as our new energy system grows, and as renewable energy sources become more and more important, concentrated solar plants will become important for filling specific niches.

Offshore wind

Like solar panels, wind turbines on land are subject to variability as the wind picks up and dies down. But offshore, the wind blows stronger and steadier. The waters off New England have some of the best wind resources in the U.S.

But while wind turbines have spread across land like mad in the last ten years, offshore wind turbines are just getting started. They’ve proliferated in waters across the Atlantic, with Denmark and the UK making good use of them. But offshore wind has not yet gotten past the planning and testing phase in the states. That’s likely to change soon, though.

The Department of Energy has been working with developers to bring offshore wind farms to American waters. Several projects are in planning, and seem to be serious about moving forward. In fact, two projects off the coast of New England plan to begin construction next year – that’s very soon, in the timeline of these kinds of projects. It very much looks like we’ll see offshore wind turbines in America in the near future, and the industry will be watching these first forays into the field very closely.

Wave and Tidal Power

Compared to the other technologies above, wave and tidal power is lagging behind. It’s a field with a history of big plans, but most of them never get off the ground. But it’s clear that the waves and the tide represent a great untapped source of energy. The Bureau of Ocean Energy Management estimates that waters off the continental US could provide 470 terawatt-hours per year. And there’s no shortage of ideas for how we could harness it. At this point, the industry is waiting for a trailblazer, someone to establish some standards, to learn from mistakes, and to put in place a production system. The technology exists, but there’s a long road before the economies of scale and the realities of business will allow ocean energy to be a major player.


But the best way to deal with the problem of variability is not a technology at all. It’s a strategy, and a way of managing our energy needs.

Each energy source has positives and negatives. No energy source is free from environmental impacts, and no energy source provides just the right amount of energy at just the right time.

So communities are finding new ways to do what they’ve been doing all along: building diverse energy portfolios, with energy sources that can make up for each other’s risks and shortcomings.

Maybe it’s as simple as installing solar panels on a different side of the house. Individual energy producers want to angle their solar panels to maximize their exposure to the sun and maximize their output. But maybe it makes more sense to reorient some of them, to increase their exposure later in the day, when the energy they produce would be higher in demand and higher in value.

In the past, large utilities bought and sold power based on the demand and supply as they saw it. But with more and more consumers generating their own power with solar panels, and more and more small energy generators plugging into the system, utilities have less control over the power grid than ever before.

All of the technologies above – large-scale batteries, concentrated solar, offshore wind, ocean energy – each fills a different niche. And it’s going to be more and more important that each renewable energy technology we have balances our others, and balances our system as a whole.


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