Simpler Solar Solutions

Advancing technologies have drastically boosted efficiency and cut costs over the years to make solar energy far more affordable, practical, and irresistible across the Golden State. But our developments and investments in giant, cutting-edge solar “farms” that harvest, concentrate, and then distribute energy to millions of distant users has unintended consequences. These developments have encouraged Californians to rediscover how so many of their energy solutions can be found right in their own homes, businesses, and backyards. Billions of energy dollars, tons of natural resources, the health of our communities, and huge expanses of our public lands are at stake.

California was a leader in fossil fuel extraction and use during the 20^th Century. This landscape near Lost Hills just above the San Joaquin Valley reminds us that all of our energy sources have their impacts. And even here, we are using indirect solar energy in the form of ancient plants and other biomass that once flourished in sunlight. The energy was trapped and cooked into an underground stew for millions of years until we brought it back up to fuel our engines and industries.

The development and use of affordable renewable energy and our increasingly more efficient use of resources is keeping tons of pollution out of our air, water, and soil, while saving Californians billions of dollars in the long run. Millions of people and entire ecosystems are healthier as California helps to lead the nation and the world toward a cleaner and more promising energy future. As the state’s per capita energy use and greenhouse gas production continues to decline, individuals, households, and businesses have discovered a treasure trove of long-term savings that can be routed to improve the quality of our living and working environments. But since the devil is often in the details, what are these sources of energy and how reliable are they?

As we race through the 21^st Century, each of these economic sectors contribute to California’s enormous but decreasing greenhouse gas emissions. How will future diagrams change as we continue to improve our efficiency? Source: California Air Resources Board.

The Golden State is progressing toward a challenging goal of 100% “clean” electricity by 2045. But it is important to note that, by 2022, such “clean” sources (according to the California Energy Commission) included all renewables (39+%), large hydropower (≈11%), and what remains of nuclear (≈11%) in the state. Solar, wind, geothermal, biomass, and small hydropower are considered renewables. But there’s something missing here that I’ll call small solar power (often referred to as passive), though it isn’t small at all, since it’s working for us everywhere on every day and it is the source of almost all the energy that surrounds us.

Californians are responding to gradually warming temperatures by using less energy to warm their spaces and more energy to cool them as we progress through the 21^st Century. And most folks continue to discover that most reliable waste-not, want-not source of energy: efficiency.

As temperatures gradually warm, people in all California regions continue to use less energy to heat and more energy to cool their spaces over time.

The energy industry often divides active solar into two categories: solar thermal and solar photovoltaic. The larger projects have generated tons of controversy. For instance, the Ivanpah solar thermal facility, with a price tag of more than $2 billion, was touted as the world’s largest. You can’t miss it if you are driving through the Mojave Desert along Interstate 15 just before crossing into Nevada. This is where once wild open desert has been covered with giant mirrors to focus intense sunlight toward 450-foot towers where high temperature steam turbines generate electricity. The electricity is sold to you through companies such as PG&E and SCE, but millions of dollars of electricity are lost through wires transmitting it to distant urban centers. Meanwhile, the desert along Interstate 10 to Arizona is being covered with photovoltaic panels on BLM land that is now known as The Riverside East Solar Energy Zone. This includes the sprawling Chuckwalla Valley, which has become a sea of solar panels that has also been advertised as the largest such project in the world. In both of these gargantuan solar energy “farms”, enormous expanses of open public desert ecosystems have been sacrificed to gather and concentrate solar energy and convert it to electricity that then must be sent out to urban areas more than 100 miles distant.

The massive Ivanpah solar thermal facility is located near Interstate 15 and the Nevada Border. From a distance, the solar panels resemble a giant lake.

As with other major power plants, these solar “farms” come with plenty of baggage. Habitat destruction haunts each project. Thousands of birds and other wildlife have been unintentionally killed each year by these behemoth projects. Precious groundwater supplies have been threatened. Desert dwellers and cultures that include Native Americans have also been impacted.

The Ivanpah solar facility has covered a big chunk of this desert. Impacted wildlife incudes unfortunate birds that are zapped by the intense concentrated heat directed toward the towers.

Desert devotees wonder why more solar panels are not being installed on top of existing warehouses, parking structures, homes, and businesses, in urban areas where the energy is being used. Even when the cost of storage batteries is added to solar installations, the payoff time is often less than 10-15 years, when consumers begin getting their solar energy for free for the life of panels that can last more than 30 years. And when homes or businesses with existing solar systems are sold, the seller gets more than their investments back from the added sales prices. Those who don’t want to pay upfront costs and take responsibility for owning and maintaining their solar systems are enticed by lucrative leasing arrangements; customers benefit from less expensive energy after paying a monthly fee to the companies who own and lease out the systems. Millions of rooftops and other urban spaces (including those for vital battery storage) are still waiting to harvest and store otherwise wasted and increasingly competitive solar energy for the taking. So why aren’t more families and businesses being encouraged to make such smart investments in otherwise underused urban spaces that can guarantee long-term profits?

Plenty of energy is being used to support economic activities in this industrial landscape that is home to LA’s rail yards. Long ago, the Los Angeles River was “tamed” and channeled around downtown, encouraging industries to locate right along the river. And now, you can see why some might imagine this to be an ideal setting to harvest solar energy that can be used locally.

You can see why the chorus of concerned citizens and energy experts advocating for more efficient, local energy production is growing louder. They argue that many of the most competitive sources of future energy can be found on our roofs and in our cities where energy is used and that destroying distant public lands and ecosystems is not sustainable. They also argue that local energy issues and problems can be more efficiently addressed with local solutions that help consumers gain control of their power sources. Similar controversies have swirled around some of the ubiquitous wind turbines that have sprouted above rural and remote regions across the state. I address some of these issues in my new book, The California Sky Watcher.

Health clubs, restaurants, and other businesses discovered the advantages of free natural light and clean, fresh air during and immediately following the COVID pandemic. These healthy open-air environments attracted patrons who were fearful of catching the virus in closed spaces. What did we learn from these back-to-nature business and energy savers that moved outdoors to take advantage of California’s mild climates?

And that leads us to the simpler and more pragmatic sustainable energy solutions sometimes known as passive solar. They often involve common-sense and time-tested planning with nature in practical ways that will allow us to save money, gain control of our energy destiny, and improve the quality of our living and working environments. Such solutions have been under our noses and calling out to us all this time.

You will find this Living Roof at the California Academy of Sciences in San Francisco’s Golden Gate Park. Plants, solar panels, and skylights compete for space up here. From the Academy: “The Living Roof provides excellent insulation (reducing energy needs for heating and cooling), captures 100% of excess storm water (preventing runoff from carrying pollutants into the ecosystem), and transforms carbon dioxide into oxygen—just for starters.”

Many of us have already discovered the advantages of greenhouses, skylights, sunroofs, and sunrooms that allow natural sunlight in, rather than relying on artificial energy-consuming light and heat sources. And this reminds us that almost all the energy surrounding us is direct or indirect solar. It’s the energy plants use to grow and that animals store as they eat. Whether you are a vegetarian or an omnivore, you are using indirect solar energy to read this page and walk across the room. As covered in stories from my new book and on this website, solar energy creates temperature gradients that build pressure gradients that propel the wind. The sun’s energy evaporates water and lifts moisture into the air to fuel storms that provide life-giving precipitation. There it is, always surrounding us. Because there’s far more solar energy than we will ever need, we need to continue to find more efficient ways of harvesting, storing, and using it.

From the California Academy of Sciences: “Edged by solar panels, the roof’s seven hills are lined with 50,000 porous, biodegradable vegetation trays made from tree sap and coconut husks. An estimated 1.7 million plants fill the trays, their roots interlocking to create an extraordinary oasis for birds, insects, people, and other creatures.”

The simplest acts include opening windows during the day and closing them before sunset during the cool season. During warm summers, keep them open at night through early mornings and then close them when daytime temperatures rise outside. You will keep fresher, healthier air circulating during the comfortable open times and prevent sick building syndromes that can develop in closed spaces. Investments in efficient ventilation systems also cut AC costs in the long run. Plant deciduous vegetation along south-facing walls to shade the hot side of the house during summer; they will lose their leaves to allow more light in during winter. Follow the source of light and heat by keeping track of the sun’s location in your sky as it changes during the day and the seasons. Eaves and overhangs can be just the right length to shade walls and windows from high summer sun during summer afternoons and then allow direct sunlight to warm those surfaces when sun angles are lower during winter. Think of the dozens of other ways you can reconnect to the natural world in and around your own living and working spaces, relieve nature deficit disorders, reap the physical and mental health benefits, and save money in the process. After all, we are fortunate to live in plein air California, not Chicago.

This diagram was intended to show noon sun angles in New York, but it also works fine for northern California, which is at the same latitude. Notice the 47-degree difference in sun angles between the winter and summer solstices. Seasonal differences are the same in southern California, though sun angles are a bit higher.

From the California Academy of Sciences: “Our living roof is more than beautiful—it’s the heart of the Academy. Weather stations on the roof monitor wind, rain, and changes in temperature to help inform the building’s automated systems and skylights, keeping rainforest temps just right, the interior piazza cool and comfortable, and natural light streaming to the exhibits below.

The best California architects know how to design smart buildings with more sophisticated passive solar features. It might take a little more planning ahead, but such short-term investments will lead to long-term rewards that just keep on giving. Double-paned energy-efficient windows (with Energy Star ratings) and doors and improved insulation have become the standard for good reasons: these upgrades cut energy costs as they allow you to better regulate the air in your home or business when temperatures become uncomfortable outside. Here is just one website from the U.S. Department of Energy that summarizes passive solar strategies. Here is another good introduction. You can also encourage efforts to become more efficient by supporting nonprofit organizations such as Sustainable Works. They have helped thousands of students, residents, and businesses save money while they also cut pollution and save our valuable resources.

When you visit the Academy’s rooftop, you will find informative signage telling green roofs stories. This cutting-edge demonstration roof is far more sophisticated and advanced that what most architects with limited resources can design, but it serves as a good example of how much we have learned and how far we have progressed.

Such simple passive solar diagrams (this one credited to Sheer Hamam) are floating around popular websites such as Wikipedia.

This passive solar diagram (displayed on Wikimedia Commons) includes some more detail.

We all use energy that can have negative impacts. But we are rediscovering how to create more comfortable, healthier living environments that will limit those impacts and save money in the long run. Sometimes it’s as simple as going back to nature. But it also requires that we work together. And in the bigger picture, that’s where Community Choice Aggregation (CCA) has made major progress across the state. At least 25 CCAs serve more than 200 communities in California that work together to pool their electricity loads, increase efficiency and grid resilience, and encourage renewable energy projects. The combination of simpler solar solutions outlined here, CCAs, and countless related efforts are moving the state toward a much greener and cleaner energy future … and proving how every Californian can make a positive difference.