At the peak of the technology bubble in March of 2000, spending on Internet infrastructure had exploded, Cisco Systems had a market cap of $578 billion, and venture capitalists were pumping millions into anything that ended in “.com.” Over the next three years, 655 telecom companies would go bankrupt, and $5 trillion in market cap would vanish from stock exchanges.

A disaster, right? It felt like one at the time. Raising money for an Internet startup became nearly impossible on Silicon Valley’s Sand Hill Road. Yet all that investment in the infrastructure of the Internet—the switches, the routers, and the fiber optic cable—drastically reduced the costs of bandwidth and made possible the applications layer, the things we love about the Internet—Twitter, streaming movies, cloud computing. Today we use information technology to do things we didn’t imagine circa 2000, like buying shoes without trying them on first. All this was accomplished with software and clever ideas for better using the available infrastructure.

We see in this story important analogies with clean energy. Advanced biofuels, electric cars, and solar power are living through their own boom and bust times. The cost of solar panels has fallen from over $4.00 per watt to less than $1.00 in just four years. That’s bad for solar investors, and panel makers are struggling to survive. Some have gone out of business. But at the same time, infrastructure is being built. Spending on solar, wind, and other forms of renewable energy has exploded, reaching $250 billion per year.

Raising venture capital for capital-intensive clean tech, especially for early-stage companies involved in new types of energy production, has become increasingly difficult. That has investors like us thinking about new ways to apply our dollars to the energy problem. We believe the next opportunity is what we call the “cleanweb”—a form of clean tech that takes advantage of the Internet, social media, and mobile communications to alter how we consume resources, relate to the world, interact with each other, and pursue economic growth.

We think that IT and fast-growing Web business models can expand the use of renewable energy. These days the challenges that industries like solar, wind, and biofuels face are often not about fundamental science. Many of the big breakthroughs have already taken place, and in some circumstances, electricity from wind and solar is already cheaper than electricity from fossil fuels. What hampers these industries now is poor sales channels, complex financing and incentives, and a failure to communicate with consumers.

That makes them ripe for disruption by the application of information technologies, which will drive the next phase of cost reduction and implementation, especially for solar. The price of a rooftop solar installation has dropped by half in the last few years, but the reductions in panel prices can’t continue. Now more than half the price of a home solar array is made up of soft costs like site evaluation, customer acquisition, and financing. On average, solar companies spend $2,500 to acquire each new customer. Imagine the frustration when after sending a truck out to a home, an installer discovers that a tree shading the roof makes the project uneconomical or that the customer doesn’t qualify for financing. That’s a significant waste of time and money.

Better information can reduce these inefficiencies. OneRoof Energy, for example, a solar company we’ve invested in, uses satellite imagery to remotely work up a customer’s project, determining its cost and viability long before a truck ever rolls out to the house. Another company we’re backing, Solar Mosaic, is raising money for solar installations via online crowdsourced loans. We estimate that IT-driven solutions alone can reduce solar costs by another 75 percent; if so, solar could become decisively cheaper than electricity from coal. Eventually it could account for 15 to 20 percent of U.S. electricity needs.

Unlike traditional clean tech, the clean Web doesn’t always have to do with producing energy. Consider peer-to-peer online markets that foster collaborative consumption. Airbnb is an online service that allows consumers to rent local accommodations in people’s homes instead of hotels. The company probably wasn’t founded with energy efficiency in mind, but given that hotels are three times as energy intensive as the average home, the cumulative impact of reducing hotel use could be significant. The company rents more than 10,000 rooms nightly; while that’s less than a tenth the number of hotel rooms in Las Vegas, keep in mind that these savings are organized almost entirely through a computer program, and Airbnb is growing extremely fast (see map). That’s the idea: obtain clean-technology benefits at the speed and scale the Web can create.

Restructuring markets to save resources isn’t confined to hotels and the built environment. Car sharing is on a rapid growth curve: the number of shared vehicles rose from a little over 1,400 in 2004 to over 12,000 last year. Car-sharing leader Zipcar claims that every one of its shared vehicles is displacing the need for 15 others. At today’s volume, that’s 190,000 vehicles that don’t need to be built. IT that facilitates videoconferencing and telecommuting cuts down on energy use, too.

Computer programs are only as good as the data we feed them. That is currently a major limitation, but it’s one we see being rapidly overcome. There are currently 2.5 billion sensors connected to the Internet, such as GPS locators on shipping pallets and even volume sensors on trash cans. That number is expected to grow to 100 billion in the next 10 years. With the emergence of this “Internet of things” will come a vast increase in data that can be sliced and diced, creating new opportunities to unearth patterns and possibilities for energy savings.

Utilities across the U.S. had installed 26 million smart meters on homes by the end of last year, and the same is occurring in China and Europe. These meters, combined with sensors in dishwashers or thermostats, will produce much more detailed information about a home’s patterns of energy use. Using this information, consumers will be able to shift energy use to times when it’s least expensive. The White House’s Green Button initiative, which gets utilities to provide customers with their energy-use data, will go a long way in enabling the army of developers out there to create the next great home energy app.

According to the Cleantech Group, venture capitalists invested in 414 cleanweb financing rounds since 2009, representing 18 percent of all clean tech deals. Entrepreneurs, designers, and engineers are coming together in weekend-long hackathon events around the country to see what kinds of apps they can create in 36 hours using public data, like efficiency rankings of refrigerators sold on Amazon.com or the energy profiles of public buildings. We’ve held events in San Francisco and New York City, and a half-dozen more are planned this year. We’re still at the very beginning of this movement. But more people are beginning to understand that the application layer of tomorrow’s energy technology is being written today.

Sunil Paul and Nick Allen are partners at the venture capital firm Spring Ventures in San Francisco.