By Andrea Thompson
Solar panels perched on the roofs of houses and other buildings are an increasingly common sight in the U.S., but rooftop wind systems have never caught on. Past efforts to scale down the towering turbines that generate wind power to something that might sit on a home have been plagued by too many technical problems to make such devices practical. Now, however, a new design could circumvent those issues by harnessing the same principle that creates lift for airplane wings.
Overall, electricity generated by renewable sources has grown in the U.S. in recent years, and wind power has been a major driver of that trend. It accounts for more than 40 percent of electricity from renewables in the U.S. (though only 7 percent of all electricity production). Unlike solar energy cells, which are limited to collecting energy during daylight hours, wind turbines can run all night in any place with the right conditions—namely, in open plains or gentle hills with consistently sufficient wind speeds. But in addition to those requirements, large turbines need open space, which is not always available near towns and sprawling cities. Installing rooftop wind systems on homes and city buildings could help harness more of this resource.
When it comes to wind power, size matters. The amount of energy an individual turbine can generate is proportional to the area its blades sweep—so devices that are small enough to fit on a roof are less powerful. "What's kept distributed wind from being successful is that most of the systems are basically miniaturized wind turbines," says Brent Houchens, a mechanical engineer at Sandia National Laboratories. The smaller devices do not produce enough energy to be cost-effective. Plus, their quickly spinning blades create noisy vibrations, and their many moving parts are more prone to breakage. Compared with passive rooftop solar panels, wind turbines have the potential to be quite high-maintenance.
Houchens and his colleagues think they have engineered a solution that overcomes these obstacles by borrowing from a fundamental principle of air flight. The curved shape of an airplane wing—called an airfoil—alters the air pressure on either side of it and ultimately produces lift. Houchens' colleague Carsten Westergaard, president of Westergaard Solutions and a mechanical engineer at Texas Tech University, says he hitched two airfoils together so that "the flow from one airfoil will amplify the other airfoil, and they become more powerful." Oriented like two airplane wings standing upright on their side, the pair of airfoils directly face the wind. As the wind moves through, low pressure builds up between the foils and sucks air in through slits in their partly hollow bodies. That movement of air turns a small turbine housed in a tube and generates electricity.
Thanks to this design, the device—which the researchers call an AeroMINE ("MINE" stands for Motionless, Integrated Extraction)—can pull wind energy from a larger area (essentially, the AeroMINE's rectangular face) than its turbine blades could on their own in a traditional setup. Houchens likens such standard turbines to cookie cutters that leave wasted dough behind. The new device makes use of all the available wind, allowing it to extract more energy.
AeroMINEs also do not generate the same vibrations and noise as regular turbines; they are "less noisy than a ventilation fan," Westergaard says. The relative simplicity of their design means there are fewer moving parts to malfunction. The turbine, which is housed inside a building, would be easier to access if it does need repairs. This arrangement also keeps the blades isolated from any contact with people or wildlife. The team is designing the system so that it could be used in conjunction with rooftop solar panels, plugging into the existing infrastructure to harvest the energy they generate.
"I do think this technology could be groundbreaking" for areas with good wind conditions, says Luciano Castillo, a mechanical engineer at Purdue University, who is not involved in the project but has worked with Westergaard in the past. He also thinks the simplicity of AeroMINEs could make them a good option for developing countries, because the new devices do not require specialized parts or tools and are relatively easy to fix. Castillo and Westergaard both see the potential to use the design underwater to harness tidal energy as well.
Jay Apt, co-director of the Carnegie Mellon Electricity Industry Center, who is also not involved in the project, agrees that the simplicity of the design is attractive. But he is unsure whether the system can be scaled up to efficiently generate energy at a low enough cost in a real-world setting. Houchens says that with suitable wind conditions, he and his colleagues think AeroMINEs can be competitive with the current cost of rooftop solar power.
The team, which has received funding from Sandia and the Department of Energy, has tested scaled-down models in wind tunnels to fine-tune the design. In June the researchers have plans to test a four-meter-tall version of the device on a single-story mock building at the Scaled Wind Farm Technology (SWiFT) facility, part of Texas Tech's National Wind Institute.
This story originally appeared in Scientific American and is republished here as part of Covering Climate Now, a global journalism collaboration strengthening coverage of the climate story.
By Bret Stetka
Glaciers continue to melt. Sea levels are on the rise. And now scientists believe the changing climate may put our brains at risk. A new analysis predicts that by 2100, increasing water temperatures brought on by a warming planet could result in 96 percent of the world's population not having access to an omega-3 fatty acid crucial to brain health and function.
That molecule is called docosahexaenoic acid, or DHA. It is the most common fatty acid in the mammalian brain and plays a key role in the survival and function of our neural cells, especially during the organ's development. Data suggest that not having enough of the compound may increase the risk of conditions such as depression and attention deficit hyperactivity disorder and impair cognition in people with early dementia.
Our bodies do not make much DHA, so, for the most part, we obtain it through diet. Plants and meats have modest amounts of the fatty acid, but the most abundant source by far is fish (or fish-derived supplements). Fish obtain DHA by consuming algae. The authors of the new study predict that rising temperatures could disrupt algal DHA production and lead to a 10 to 58 percent reduction in availability of the compound, depending on the geographic region.
To predict the future of DHA availability, they used data from the Food and Agriculture Organization of the United Nations and the fishery research institute Sea around Us to get numbers on how much edible fish are caught and farmed worldwide each year and on how much of that maritime tonnage is composed of DHA-containing fat. Then, using data showing how temperature influences algal DHA production, the researchers determined roughly how much of the fatty acid is presently available by consuming fish per capita versus how much will be available 80 years from now.
Their predictions show that larger countries with rapid population growth in East and Southeast Asia — including China, Japan and Indonesia — will face the most severe DHA shortages. Most African countries — especially landlocked ones — will also end up falling below recommended DHA intake, whereas nations with small populations and active fishing industries, such as Norway, Chile and New Zealand, will likely maintain access to adequate omega-3s.
"I already had an idea that DHA would decrease, based on previous data," recalls Stefanie Colombo, an assistant professor in aquaculture nutrition at Dalhousie University and co-lead author on the new paper. "But I was surprised and concerned when we saw the decline in DHA per capita—that people in some areas of the world would be more affected."
Tom Brenna, a professor with joint appointments in pediatrics, chemistry and human nutrition at the University of Texas at Austin, points out that the new results are open to a range of interpretation: "The [predicted] interval of 10 to 58 percent is so large as to be the difference between a mild inconvenience and a calamity." Yet he welcomes any investigation into the global DHA supply.
Brenna, who was not involved in the new study, also points out that whether or not dietary DHA is necessary in adults has been an area of conflict for decades. Yet he and most experts in the field agree that it is a critical nutrient during brain development and even into the late teen years — and that its influence on brain function may vary, based on an individual's genetic profile.
Omega-3 fatty acids can be derived from terrestrial sources, including nuts, seeds and land animals. Yet as Michael Crawford, now at Imperial College London, discovered in the 1970s, "ready-made" DHA — such as found in fish — is incorporated into the developing brain with 10-fold greater efficiency than plant-sourced DHA.
Crawford is a pioneer in understanding the relationship between omega-3 fatty acids and brain health and believes that the evolution of our big and complex primate brain would have been impossible without access to DHA. He also thinks that a decline in consumption of omega-3s because of our increasingly processed diet explains increasing rates of mental illness and declining IQ. Marine agriculture such as projects now underway in Japan might be essential to saving ourselves and the planet. "If mental illness continues to escalate, then Homo sapiens are finished," Crawford predicts. "Seventy-one percent of the planet's surface is water, and marine cultivation will help reverse this trend. Without farming the seabed and oceans, food security goes out of the window."
Aquaculture initiatives abound throughout the world, including those intent on farming algae as a source of DHA. Other researchers are using genetic engineering to grow plants with a more available form of the fatty acid. And Richard P. Bazinet, a professor in the department of nutritional sciences at the University of Toronto and a co-author of the new paper, is working to understand how DHA enters the brain and how much of it a healthy adult brain actually needs.
Colombo is hopeful that in the face of a changing climate, scientists will devise new sources of DHA. And she plans to study how warming waters will affect fish metabolism and DHA availability. Yet she admits the outcome does not look good: "I don't think this is something we can ignore. In terms of the climate warming, we can't continue on this same trajectory."
Omega-3 fatty acids are essential fats that have numerous health benefits. This article takes a detailed look at the 3 most important types of omega-3shttps://t.co/I8K8jqZiUl— Frank Lipman MD (@DrFrankLipman) July 10, 2019
This story originally appeared in Scientific American. It is republished here as part of EcoWatch's partnership with Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.
Installing solar panels is a great option for homeowners who want to reduce their power bills, and the payback period can be just a handful of years with favorable conditions. However, renters and apartment owners cannot use a typical solar power system due to the lack of space, and renters in particular must also negotiate with their landlords. A miniature solar system that is portable and easy to install can be a better option in these cases.
Rooftop solar systems can greatly reduce your electric bills, and you can add solar batteries to store solar energy for use at night. However, because most systems are tied to the power local grid, you must meet many technical requirements and get a permit to put solar on your property. The initial investment and paperwork are not a problem when installing solar panels in a home you own, but they're a limiting factor for renters.
If you don't own your home or apartment, you may have little incentive to invest in improving someone else's property. Even if your landlord gives you permission to install solar panels, the decision only makes sense financially if you plan to rent for a very long time — longer than the solar payback period. Also, consider the following factors:
- When your lease ends, your landlord may not be willing to purchase the solar panels you installed.
- Moving rooftop solar panels to another home is difficult, and you will need a professional installation and another permit for the new property.
There are many types of miniature solar systems that can be installed without the complex requirements and permitting procedures of more permanent structures. These systems are an excellent option for renters, since taking them to another property is as simple as relocating your TV.
Solar Benefits for Non-Homeowners
Solar panel systems offer a common benefit, regardless of their size: they generate electricity from sunlight, reducing the amount of electricity you must pay your utility company for each month. Solar power also lowers the environmental footprint of your home, especially if you live in a region where most of the grid electricity comes from fossil fuels.
Homeowners get a few extra benefits when they install a traditional solar system, including:
- Their property becomes more valuable, and many states don't charge increased property taxes for the portion of home value that corresponds to solar panels.
- Homeowners also qualify for the 26% federal solar tax credit as well as any additional incentives from state governments or utility companies.
- There are permitting and grid connection requirements to meet, but once the solar PV system starts operating, it provides electricity for decades with minimal maintenance.
While mini solar panel systems may not be eligible for these perks, they have their benefits compared with rooftop systems. For example, they are much easier to install, with no permitting involved, and any maintenance is much simpler. Small-scale solar systems also have a lower price, and they are easily relocated.
The power bill savings achieved by a rooftop solar system are much higher, but that's because they're much larger. Many homeowners use solar PV systems that have capacities at or above 6 kW (6,000 W), while miniature systems often only generate up to 100 W. As you might expect, the corresponding cost of solar panels is very different: A 6 kW solar system can cost around $18,000 (before incentives) to install, while a miniature 100 W system might cost less than $300. However, each dollar invested is earned back multiple times over in both cases.
How to Utilize Solar Energy When You Rent
There are several options for renters who want to use solar power. These include:
- Plug-in mini solar systems
- Off-grid solar and battery systems
- Portable solar panels
- DIY solar setups
- Appliance-specific solar panels
Plug-in mini solar systems work exactly like rooftop PV systems — they connect to your residence's wiring and synchronize with the voltage and frequency of your grid power — just at a smaller scale. The power generated by a plug-in mini system is usually enough to power several electronic devices and LED bulbs, but not high-power devices like air conditioners and washing machines.
Here are some things to consider when deciding whether a solar plug-in mini system is right for your rental property:
- Plug-and-play solar panels are not subject to the permitting requirements and interconnection procedures of a traditional rooftop installation, and they can be simply connected to a suitable power outlet.
- NOTE: When using plug-in solar panels, you must make sure that the power outlet used has a circuit with enough capacity to carry the current, as well as an adequate breaker. Otherwise, you can cause an electrical fault.
- Because this type of panel connects to the electrical system of the property, you should ask your landlord for permission before investing in one. You should also ask an electrician to check the power outlet you plan on plugging the panels into to make sure it has adequate capacity.
Off-grid solar panels and solar battery systems are completely disconnected from the grid, which makes them a popular option for remote or rural sites with no electric service. In these types of systems, one or more solar panels are used to charge a battery or solar generator with USB charging sockets and power outlets for small appliances. These off-grid systems are also a viable option for renters, because they are entirely self-contained and don't connect to the utility grid.
Portable solar panels are popular for camping, but they can also be used by renters to power small devices. These are some of the smallest solar panels available, and they only have a few watts of capacity. Their main purpose is charging smartphones, tablets and other tiny USB devices, and many of them have built-in LED flashlights.
DIY solar panel setups are also an option. You can shop online for compatible solar panels, inverters, batteries and solar charge controllers, and then build a custom system according to your needs. However, keep in mind that you must have at least basic knowledge about electricity to safely and successfully install a homemade solar system.
Appliance-specific solar panels are also a viable option for renters. You can find many devices with built-in solar panels, which don't depend on a power outlet to operate. For example, you can install solar-powered outdoor lights for your backyard or balcony, or use a solar air conditioning unit or fan to provide extra ventilation during the hottest hours of the day.
Pros and Cons of Small Solar Units
Miniature solar systems have advantages and limitations like any device. They have a lower cost than traditional rooftop systems, plus they are easier to install and relocate. Just keep in mind that they can't power larger appliances, which means their power bill savings are small.
The following table summarizes the pros and cons of the most common types of miniature solar systems:
|Renter-Friendly Solar System||Pros||Cons||Typical Price|
|Plug-in solar system||
- Easy to install
- Can be plugged into a normal power outlet
- Can only operate when connected to the grid
- You need a dedicated circuit and breaker of adequate capacity
|$1,500 for a 600 W solar system|
|Off-grid solar system||
- Can charge batteries or generators to be used after sunset
- Fully independent from the grid
|- Batteries increase the system cost significantly if you want a high energy storage capacity||$400 for a 100 W solar panel with a 24,000 mAh battery|
- Easy to carry
- Can be used for camping and other trips
|- Limited use: Charging smartphones and other small devices||$100 or less for a foldable 30 W panel|
|DIY Solar||- You can create a custom system that meets your needs||- Basic electrical knowledge is needed to set up a safe system||Variable, depending on the components used.|
- Easy to install
- The solar panel is often included with the price of the device
|- You can only use the solar panel to power one appliance or device||Variable, depending on the appliance|
Miniature solar power systems are designed for small, low-power devices such as LED bulbs and electronic gadgets. If you're a renter and would like to increase your savings beyond what is possible with small solar kits, you can consider joining a community solar project near you.
- These projects normally have two membership options: purchasing a share or paying a monthly subscription.
- In both cases, you will be entitled to a portion of the kilowatt-hours produced by the system, and this portion will be subtracted from your bill.
Another advantage of community solar is that you can move freely to another apartment or home. Since the solar panels are not physically located where you live, you can usually re-assign the electricity savings to your new address.
Products to Help Renters Maximize Solar
There are many brands of miniature solar kits, but you should look for a reliable provider like Sunboxlabs. Since you're dealing with electricity, purchasing high-quality products is strongly advised to avoid accidents. Before purchasing any solar panel or a related component, make sure it has an electrical certification mark such as:
- UL (Underwriters Laboratories)
- ETL (Intertek)
- CSA (Canadian Standards Association)
- CE (Conformité Européenne)
You can look for a solar kit that includes all components, such as this WindyNation 100 Watt Solar Panel Kit. Alternatively, you can buy compatible parts separately, and build your own system. The following are some recommendations:
|Solar System Component||Recommended Product|
|Solar Panel||Renogy 100 Watt 12 Volt Monocrystalline Solar Panel|
|Battery||Mighty Max 12V Battery|
|Solar charge controller||ALLPOWERS 20A Solar Charger Controller|
|Inverter||BESTEK 500W Power Inverter|
Keep in mind that you will also need wiring to connect all components together, and make sure you read all instructions carefully to ensure safety.
By Andrea Thompson
In the debate over how to respond to the perils posed by the earth's changing climate, the ground has been rapidly shifting in recent years: as the Trump administration has retreated from efforts to curb greenhouse gas emissions and engage in climate diplomacy and public demand for action has grown — particularly among younger generations — cities and states have stepped into the breach.
Last Friday 16-year-old Swedish climate activist Greta Thunberg led the largest of her global climate strikes in advance of today's United Nations Climate Action Summit, an attempt to spur countries and businesses to step up their efforts at reducing carbon emissions. These calls to action come just days after the Trump administration announced it would revoke California's prerogative to set its own air pollution rules in a battle over vehicle-emissions standards. Though President Donald Trump plans to withdraw the U.S. from the landmark Paris climate agreement next year, dozens of cities and seven states, along with Washington, D.C. and Puerto Rico, have pledged to shift to 100 percent renewable energy to honor the agreement. The next few years will show whether this is a watershed moment.
During Gina McCarthy's time as administrator of the Environmental Protection Agency under former president Barack Obama, she spearheaded many of the hallmark climate regulations that Trump is now undoing. Scientific American spoke with her about why she thinks we may be turning a corner on combatting climate change, the work she is doing in her new role as director of Harvard University's Center for Climate, Health and the Global Environment and what it has been like to watch as her signature accomplishments have been dismantled.
[An edited transcript of the interview follows.]
Are we, as a society, at a turning point in our willingness to combat climate change? And if so, what do you believe is fueling that shift?
I do think that we are at a bit of a turning point. I think everybody has different views on why that's the case, but clearly, the science is getting more urgent. I think you have now a new generation of young people — such as [those in] the Sunrise Movement — and they're just not letting the rest of us off the hook anymore. They don't seem to have the same kind of reluctance to embrace the science, and they're seeing that it is their future that is at stake.
There are also a lot of things happening in the world that make climate change much more visible, such as the more intense and frequent storms that we're seeing — the fires, the floods that we're seeing. It's very hard now to ignore it and to think it's anything like business as usual — because it really isn't. So I do think there's a lot more ability for people to understand that it's not just real, but it is really here. It has an ability to impact them.
And I think it's just really important that we personalize it, and we have found that the health message is a very clear and compelling one. Climate change is the most significant public health challenge of our time. And it's showing itself not just in the developing world — with millions of people who have water and food insecurity — it's about the challenges in the U.S. that are becoming very visible to people. It's showing that health has always been inequitable — both access to it, as well as who is most at risk and most vulnerable. And it's those communities that are getting hammered by climate change.All those things come together: It's greater visibility; it's more understanding; it's better science; it's more solutions on the table. It's opportunities, as mayors and states and urban and rural communities are starting to step up. The actions that we can take are more robust than they've ever been before. And they're not sacrificial acts; they are better for us economically. So there are lots of reasons why I think people are beginning to get it and admit it and want to do something about it.
We also seem to be moving away from re-litigating the basic tenets of climate science to focusing more on solutions. How do you think science can be used to inform those policy questions?
I think the trick is to use climate as a lens in how you look at the challenges of today. You have to make sure that whatever you're doing for climate, you're looking at providing immediate benefits — health benefits, as well as economic benefits — and there are huge opportunities there.
And part of the trick is that if you're going to do that, how do you do it in a way that is more equitable and that brings value to vulnerable communities first? So part of it is not thinking about one thing but thinking of this as a system approach. [During the CNN Democratic climate forum this month, Senator] Cory Booker [of New Jersey] basically said he's going to demand that his entire cabinet looks at their work through a climate lens. That's exactly what should be done. Why wouldn't we want to have the military — who totally recognizes climate change as being a huge national and international instability issue — why wouldn't we want to support it in its interest in having renewable energy instead of fossil fuels? Why wouldn't we want to become a leader in clean energy, so we're not fighting about oil fields overseas? All these things provide opportunities for the entire complexion of the discussion to change from "I want to scare you into doing something on climate" to "Let's be smarter about federal dollars being spent and the way in which people are demanding action that's going to be beneficial for their health."
So we want to look for where there are the proverbial win-win scenarios.
Yes, because there an awful lot of them. They won't get you to zero carbon emissions, but they're building momentum. And they're providing an opportunity for the private sector to start investing, because it knows people will want it, and people will buy it. Those are the kinds of signals that that have been — how shall I say it? — less clear in this administration than the prior [one]. For somebody that wants a strong economy, [this administration is] doing it in the damnedest way. It is trying to look at what drove our economy from the industrial era and not recognizing that we're just not there anymore.
What is some of the work your group at Harvard is doing to see which solutions will be the ones that meet those climate, health and economic goals in an equitable way?
We've been doing research, in collaboration with a number of other universities, on how we look at the transportation sector. [Along with Washington, D.C.,] there are several states — [in New England and the mid-Atlantic]—that are actually getting together to develop a cap-and-trade strategy. And what we're doing for them is to take a look at the policies and do an analysis on how you can maximize the health benefits.
We're also working on some of the rollbacks [of environmental regulations] at the federal level — to take a look at the health outcomes. And we've been able to point out some significant deficiencies in those that we can submit (and have submitted) as a comment so that the EPA can take cognizance of them when it does its final ruling — and if it fails to, then that opens up the potential for litigation against a final rule.
We're also doing a lot of work in the health care sector — working with medical professionals. They're beginning to really step up and actually do work in the climate realm. There are things from preventing health problems to looking at where health problems currently exist and how we [can] design solutions that benefit them to how we actually get into the medical profession itself and do work here. [Aaron] Bernstein [McCarthy's co-director], he's been really pushing the medical profession to look at things like how heat stress can really do damage to patients if you're not thinking about the drugs that you give them — things in which the medical care profession itself needs to look at its own work and adjust because of the changing climate.
What has it been like to watch the Trump administration reverse a lot of the key climate change efforts you led while at the EPA?
Well, because you're taping this, I won't tell you how I really feel in the most graphic terms. Really, to be honest, it's very frustrating to keep up with, because [the administration is] doing things gratuitously. On the Mercury and Air Toxics Standards — which is the first limit on mercury emissions from power plants — the major lobbyists for the utility sector wrote to the current EPA administrator and said, "Don't touch it. We've completed it. You're going to cause us stranded assets, because we'll have all this equipment that we're no longer required to run, and that means we have to pay the bill for it in regulated sectors." And [the EPA] still went ahead and did it. It's about emissions of neurotoxins that directly impact fetuses and young kids, and since we did the Mercury and Air Toxic Standards, the amount of mercury being emitted has taken a nosedive. It's just frustrating to me.
And then [the administration] goes on to do the car rules [to lower fuel efficiency standards]. And the only fun thing about that is it was taking such a drastic sort of rollback on an industry that needs years of certainty to be able to figure out what to make. So you've got some of the largest car companies — such as Ford, Volkswagen, Honda, BMW — that have run to the welcoming arms of California regulators. Go figure how a president figured out how to do that. So my head spins.
One of the good things is that [the administration is] very poor at regulating and analysis. It's looking to get an outcome — not follow the science and not follow the law — which means it has somewhere in the area of an 8 percent success rate in the courts [when rules are challenged].
[The administration also has] an inability to recognize that one of the federal government's best tools to grow the economy — and one of our best tools to remain the strongest economy in the world and compete against China — is not about Paris [the 2014 climate agreement]. It's about federal dollars being invested wisely in innovation. That's what the federal government does. There's always years of a gap between a technology being devised and tested and ready to go and when it gets a significant enough amount of the market share that it's costs drop, and it becomes truly marketable. That's the gap that's always been filled by federal dollars. And the really sad thing is while [Trump] is yapping about Paris, we're seeing China eat our lunch on cars and on renewable energy and equipment. We're just losing ground, in terms of our ability to grab the clean energy economy and turn it into jobs and economic growth for us.
And that's perhaps, in the end, the most damaging legacy of this administration: this willingness to look backward and to think that our future is about being oil-independent. It just amazes me that it hasn't at all recognized where the world is today and where it ultimately will head — whether this president likes it or not.
Andrea Thompson, an associate editor at Scientific American, covers sustainability.
This story originally appeared in Scientific American. It is republished here as part of EcoWatch's partnership with Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.