On the very first Earth Day in 1970, 20 million Americans gathered to protest the industrial revolution, launching an environmental movement that has lasted since. Every year, people around the world spend some time planting trees, collecting garbage, riding bikes, and generally raising awareness about environmental protection.

The thing is, Earth Day — and environmentalism in general — isn’t just a hippie movement anymore. Protecting the Earth has everything to do with technology, from renewable energy to big data to conservation.

We’ve written a lot about these topics on TechRepublic in the last year or so. Here’s a roundup of the top 10 stories.

1. How tech companies are propelling the environmental movement, and why it’s time to do more

Our last longform of 2014 was about how tech giants are pushing the environmental movement forward. It largely focused on Greenpeace’s reports about tech companies powering their data centers with renewable energy (Apple and Google are making huge strides in this direction) and how Amazon Web Services needs to stop powering the majority of the internet with coal.

2. How cleantech-as-a-service will drive renewable energy adoption

This story was from the Cleantech Forum in San Francisco in March 2015. The theme of the conference was using cleantech as a service to decentralize the energy industry and get startups and investors interested in clean energy adoption. It’s an important topic because tech companies have a unique opportunity in this industry.

3. WWF spotlights the tech that is conserving the planet

At SXSW Eco, we covered a panel run by the World Wildlife Fund that concentrated on the ways technology is helping conservation efforts around the world. This includes big data, drones, and local solutions to stop poaching and other illegal activities.

4. 10 facts about the smart grid: IT’s role in unlocking clean energy

This one is huge for technology, because the smart grid requires innovations in hardware and software solutions to work. For IT professionals, that means job growth. This article highlights some of the most important facts about the smart grid and microgrids.

5. How crowdfunding solar power is democratizing the way we finance clean energy

The solar industry has grown exponentially since this story was written in March 2014, but it was a kickoff to some of our coverage of this renewable source that has become so prominent. Solar has seen incredible growth in the US, increasing more than 30% in 2014 from the previous year, according to the Solar Energy Industries Association and Greentech Media Research.

6. The state of the Industry Cloud in the energy sector

The special feature for ZDNet in April was about the industry cloud. One of those verticals we covered was energy. It mostly focused on solar, where there are software companies focusing on making data easier to gather and monitor, so that residents and businesses can be energy efficient.

7. Apple, Cook, and the power of evil empires doing good

This editorial on TechRepublic earlier this year was about the power of Apple’s environmental efforts, and how Tim Cook is leading the way in the tech industry. Though it may have seemed so at first, Apple isn’t all talk when it comes to sustainability — though the company has a long way to go,

8. 10 reasons cleantech made a comeback in 2014

This piece we ran at the end of 2014 was about why cleantech made a comeback in 2014. It really did — due to crowdfunding, next-gen battery technology and storage capabilities, software, and big data.

9. Intel looks to teen scientists to improve solar power, cybersecurity, and cancer research

Let’s talk about how awesome it is that teens are interested in solving the Earth’s problems and spending all their time trying to create the most efficient solar cells. Because it’s incredible. This story looks at Intel’s contest for students — and several young women were finalists for their cleantech research.

10. The recycled plastic filament that could set a new standard for 3D printing

3D printing is growing at an incredibly rapid pace, but if the industry isn’t careful, it’s going to create a lot of extra waste. This story is about Dimension Polymers, a company that is making the world’s first certified recycled 3D printer filament, made from scrap plastic that is washed and recycled.

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