So, What's the Best Type of Renewable Energy, Anyway?

Welcome back to Climatific, a free, weekly read that breaks down climate science so it makes sense- not for scientists or researchers, but for everyday people trying to understand the planet we live on, what’s happening to it, and why it matters.

Over the past few weeks, we’ve explored a LOT in terms of renewable energy: geothermal, nuclear, solar, wind, hydropower, and microgrids. If distilling all of the information about renewable energy is starting to feel like standing in the cereal aisle (Why are there so many options?!), that’s 100% valid.

By the end of this issue, you’ll have a better idea of how each of the types of renewable energy we discussed stack up in terms of reducing greenhouse gas emissions and bettering the climate.

If you’re a new subscriber, catch up on past issues of Climatific and learn more about who we are here:

Since March, we’ve been exploring a motley crew of renewable energy Avengers, with each playing a unique role in building a cleaner, more resilient grid.

We started this journey with geothermal- the energy beneath our feet, literally.

Geothermal taps into heat stored beneath the Earth’s surface to generate electricity and provide heating. Unlike weather-dependent renewables, geothermal offers 24/7 power generation and a small land footprint.

The catch? Geography and drilling costs still limit where projects can scale economically.

Next, we wrote about nuclear, a reliable yet reactive source of power.

It continues to spark debate, but it remains one of the few carbon-free (if you recall, not technically “renewable”) energy sources capable of delivering constant baseload power.

Our discussion focused on how its energy density affords a lot of output for relatively little land and is, in recent history, becoming a key player in our energy landscape.

The catch? Nuclear isn’t growing as quickly as solar or wind, has long lead times until it can become operational, and generates considerable amounts of radioactive waste.

We then explored agrivoltaics with Ted Gallagher, the VP of Solar at MVE Group.

Agrivoltaics is the practice of using land for both agriculture and solar energy generation. Their colocation means that solar installations can coexist with the likes of crop production, grazing livestock, and pollinator habitats.

Whirlin’ on along, we FANgirled over wind turbines converting moving air into electricity.

A few highlights from our issue:

The catch? High upfront costs, intermittent energy production, and location constraints can hinder the deployment of wind energy projects.

Last stop: Hydropower, the OG renewable giant.

Hydropower remains one of the world’s largest (literally) renewable electricity sources. By using flowing water to spin turbines, dams and run-of-river systems can generate reliable, dispatchable power at massive scale.

But dam! There are environmental costs that come from disrupting the flow of natural waters, which has ripple effects for sediment, organic material, fish, and other organisms that can get left behind without proper environmental interventions.

Thanks to calculations provided by SmartEnergy, an independent renewable energy electric supplier, we can compare our renewable energy types side-by-side in terms of the grams of carbon dioxide emissions they produce per kilowatt-hour (g CO2/kWh) of energy they produce.

Not including the indirect emissions from extraction, refining, and transportation, coal generates 1,000 g CO2/kWh of energy produced. Oil produces 730 g CO2/kWh, and natural gas produces 450 g CO2/kWh.

Now, for the renewables* (no, they’re technically not zero once you account for manufacturing, construction, and maintenance):

The bottom line: There’s no silver bullet to a clean electric grid. Each technology solves a different piece of the energy puzzle:

Increasingly, the future isn’t about choosing one source, but connecting many sources intelligently. Many of the strongest energy systems are the ones that combine multiple sources together: solar with storage, wind with hydropower balancing, geothermal with local distribution, or geothermal with grid-scale reliability.

So, where are microgrids actually showing up in the real world? Honestly, everywhere you’d want your power to not go out: a military base in a remote location, an operating room mid-surgery, a campus filled with thousands of students trying to submit final exams.

These are all places where “oops, the grid went down” is simply not the vibe. And, as it turns out, microgrids are quickly becoming the unsung heroes of energy resilience throughout all of these spaces. Here are a few of our favorite examples:

Military Bases. Military bases are increasingly using microgrids to improve energy security and reduce vulnerability to grid disruptions or cyberattacks. The U.S. Department of Defense has invested heavily in systems that integrate solar, batteries, and backup generation so bases can continue operating independently if needed.

Hospitals. Hospitals are adopting renewable-powered microgrids to maintain critical operations during blackouts. In California, one of the first islandable renewable hospital microgrids now combines solar, fuel cells, and battery storage to provide resilient backup power.

Universities. Universities like UC San Diego, NYU, and Princeton have shown that integrated campus microgrids can reduce costs while improving reliability and lowering emissions.

There are a lot of good things happening in arenas you and I might not be in, but here’s some more good news: we can be part of the solution.

Here’s how our renewable roadshow can continue with you in the driver’s seat:

If you’re an OG Climatific subscriber, you’ll remember our very first issue on Greenhouse Gases 101. We discussed that greenhouse gases act like a blanket around the Earth, trapping heat in Earth’s atmosphere and raising global temperatures. While the Earth would be too cold to support human life without greenhouse gases, humans have gone way overboard and are producing more than the Earth can tolerate to maintain its temperature.

What we didn’t talk about was why, among all the greenhouse gases we discussed, carbon dioxide (CO₂) steals the show in most conversations about emissions reduction. CO₂ is far from the only greenhouse gas, so why do we focus on it so much more than other greenhouse gases?

Tune in next week to find out. You won’t want to miss it, as it’s the primer for our next series on carbon sinks!

Have a specific topic on climate science you want to learn about? Let us know. All responses are anonymous!

As we wind down our Renewable Roadshow, here’s a recap of some of the resources we have included in previous issues (with some brand new ones sprinkled in for good measure):