There is an ongoing discussion on the relative merits of active and passive solar energy, with proponents of both types of solar energy claiming that their method has greater potential for lowering utility bills and offsetting carbon emissions than the other.
This article compares and contrasts two types of solar electricity, active and passive, and explains how you may make the most of both of these environmentally friendly technologies.
What exactly is active solar energy?
This class encompasses all solar technologies that are capable of extracting clean energy from the sun and converting it into useful form (in the form of electricity). The most well-known type of active solar power is represented by the photovoltaic, or PV, panels that are frequently located on the rooftops of homes and businesses. Nevertheless, concentrated solar power (CSP) plants, which are frequently seen on mega solar farms, are also included in this category.
What exactly is passive solar energy?
The following are some of the things that fall under this category: technology and structural designs that make advantage of the sun’s natural radiation to assist in providing:
- Heating during the bitterly cold months of winter
- Providing relief from the heat during the hottest months of the year
In application, passive solar power can be demonstrated through the use of tinted windows, south-facing (or north-facing) facades, and solar water heating.
Which is more efficient among the two?
Solar energy solutions that are passive and active, respectively, assist minimize dependency on grid electricity that is created from fossil fuels. Consequently, whether you choose to harness active or passive solar power, you will immediately begin saving money on your monthly utility bills and offsetting your carbon footprint. In addition, the costs of implementing either of these technologies will eventually be recouped, frequently several times over.
But which one has a quicker return on investment?
This is not an easy question to answer due to the fact that the two technologies serve quite distinct purposes:
- Energy production is the primary focus of active solar power.
- Reduced consumption is the result of using passive solar energy.
- Both passive and active solar energy have their perks, but the one you go with should ultimately be determined by the rate of return on investment (ROI) that you’re hoping to achieve.
What are the Benefits of Solar Energy That Is Obtained Passively?
The following is a list of some of the most significant advantages that await you if you want to investigate the possibility of using passive solar power.
1. You Do Not Require Direct Exposure to the Sun
The use of shades, tints, and sometimes even strategic landscaping in order to block out sunlight is frequently the objective (i.e., planting trees).
2. Using passive solar energy can save money.
The use of passive solar energy often does not require a significant amount of wire or equipment. Additionally, this enables you to keep costs to a minimum or at least a manageable level, depending on the scale of the improvements you are implementing.
3. Take Steps to Cut Down on Noise Pollution
Increasing the number of trees on your property or installing windows with additional insulation can help keep the temperature inside your home or place of business more stable and cut down on the amount of noise pollution that enters the building.
4. There are few costs associated with upkeep
The majority of passive solar solutions are “set it and forget it” systems, which is where the term “passive” comes from. After installing a window film or planting a tree, your work is finished. This one-time, upfront investment results in financial and environmental savings over a period of decades, all while requiring only a minimal amount of maintenance.
However, there are several constraints associated with passive solar design.
Window tinting, for instance, is a lot more cost-effective than installing photovoltaic panels. However, this modification to your passive solar heating system will only result in a small savings each month. Installing photovoltaic cells, on the other hand, may require an initial investment of tens of thousands of dollars. You will, however, make that money back numerous times over the course of more than 25 years, which is the warrantied lifetime of your solar panels.
The only way to tell which investment yields a higher return on investment is to run the numbers for your particular home or business, complete with on-site inspections from active solar and passive solar professionals. This is the only way to determine which investment is best.
However, this is not a true option because both of these environmentally friendly solutions can complement one another. To put it another way, increasing your home’s energy efficiency by utilizing passive solar techniques can assist in increasing the amount of money you save by adding photovoltaic panels, and vice versa.
What are Some of the Drawbacks of Using Passive Solar Energy?
The use of passive solar energy has a lot of positive aspects. However, there are certain problems associated with taking this strategy.
1. Fewer available design choices
In passive solar design, you are frequently limited to use whatever structural characteristics are already in place. Take for instance the possibility that there is no window that faces south. Or perhaps the angle of a wall cannot be adjusted in such a way that it would cast a shadow on the house during the middle of the day.
Even though the cost of implementing a passive solar design is frequently lower than that of installing PV panels, certain structural modifications may be either impossible or unfeasibly expensive.
2. Managing the Changes Caused by the Seasons
Passive solar architecture not only ties you down to specific structural designs, but it also makes it difficult to adapt to shifting weather patterns and changing seasons throughout the year. For instance, the shade cast by a recently planted tree will not only keep your home cooler in the wintertime, but it will also cut down on the quantity of direct sunlight that enters your property during those months.
To our good fortune, this does not hold true in every circumstance. If you insulate your windows, for instance, you may block the passage of heat, which enables you to keep the temperature inside your home at a suitable level even during the hottest and coldest months of the year.
What Are Some of the Benefits Associated with Active Solar Energy?
Passive solar design extends back millennia, but solar photovoltaic panels are a relatively recent technology that was created in the 1960s for NASA satellites and then became a commercial product in the 1980s. Passive solar design has been around for much longer than solar photovoltaic panels.
The following are just a few of the reasons why solar photovoltaic panels have gone from being an expensive niche technology to a feature that is becoming increasingly prevalent on rooftops around the country.
1. Considerable Cost Reductions on Various Utilities
The solar energy that is produced by your PV panels can be used to offset the amount of power that must be obtained from the grid. Because of this, active solar provides a guaranteed payback period in addition to a predictable return on investment – providing that the panels are constantly cleaned, maintained, repaired, and upgraded. Photovoltaic panels can mostly be installed and then forgotten about, much like passive solar energy systems. Nevertheless, during the usual PV installation’s lifetime of more than 25 years, there is a lot that may go wrong, including cracks, dust, and modules that slip out of place.
2. You are Able to Share Green Electrons (and Make Money Doing So)
The vast majority of states provide some kind of net metering or feed-in incentive that enables homeowners to sell excess solar power back to utilities in exchange for credit on their bills or cash incentives. These incentive schemes mean that in addition to shortening the amount of time it will take for you to recoup the cost of your initial investment, you will also be able to provide the rest of the neighborhood with access to the clean electricity generated by your solar power installation.
In practice, your investment in solar energy helps contribute to the overall greening of the utility system in some way.
3. Solar photovoltaic panels can help you become energy independent.
Even if the rest of the utility grid is knocked out while an outage is in progress, you will still have dependable access to daytime power provided you have solar panels installed on your roof and the appropriate kind of inverter. Additionally, if you install batteries on-site, you can store any excess solar power and use it to continue lighting your appliances even when the sun goes down.
It is conceivable to become entirely independent from the utility grid if sufficient solar and storage capacity are available. When connecting to the electrical network is not an option, this method is utilized by a large number of smaller residences and other facilities.
4. Solar photovoltaic energy provides more design options
If you decide to install solar photovoltaic panels on your home or place of business, you have a wide variety of design options to select from. Installations of solar panels on rooftops are by far the most common. However, ground-mounted PV systems and solar-enabled carports are also ideal solutions for situations in which the roof is either too small or too weak to support solar modules.
In addition, there is a theoretical cap on how much of a reduction in energy usage may be achieved by employing passive solar architecture. However, with active solar power generation, you are able to increase whatever amount of capacity that is required. If you are engaged in a feed-in tariff or net metering scheme at the state level, you will be able to convert what you don’t use into cash payments or credits toward your energy bills.
It is difficult to emphasize the financial benefits that can be gained from using solar energy. Despite this, there are still certain downsides associated with PV systems.
What are Some of the Drawbacks Associated with Active Solar Power?
While photovoltaic (PV) solar technology has many useful advantages to provide, it does have certain drawbacks as well.
1. The cost of solar photovoltaics (Upfront)
The upfront cost of purchasing a solar photovoltaic system that is large enough to provide a sizable fraction of your energy requirements is likely to be in the tens of thousands of dollars (even with the federal solar tax credit). You can choose to finance your solar energy system through leasing, loans, power purchase agreements (PPAs), or even property-assessed clean energy loans (PACE). Thankfully, solar financing has helped make the technology more accessible to those with lower incomes.
These financing alternatives are almost always designed in a way that results in your monthly payments being lower than the amount that you were previously paying to your utility provider. As a direct consequence of this, you will begin making financial gains the instant that your photovoltaic system is ready for use.
2. Solar Capabilities and Their Restrictions
There are some buildings, whether residential or commercial, that are not good candidates for solar power generation:
Sometimes the roof is too narrow or has to be upgraded (however ground-mounted systems are an option if there is enough yard space). In these cases, ground-mounted systems are an alternative.
The land does not always get an adequate amount of sunlight that is directly overhead. Cutting branches from surrounding trees is one way to lessen the amount of shade cast. However, if a nearby structure is preventing sunlight from reaching your property, there is not much you can do about it.
If you fit into this category, you may want to investigate the possibility of participating in a community solar garden. Using this strategy, you will buy a share in a significant solar photovoltaic (PV) facility that is located nearby. Even if the green electrons don’t make it to your property, they can still reduce the amount of money you have to pay for utilities. In addition, your investment in environmentally friendly energy sources contributes to the overall greening of the system.
3. Solar Power Generation Is Intermittent
Even after the sun has set, a building with a passive solar design might continue to provide benefits. Insulated reservoirs and tubing, for instance, allow the water in your solar heater to maintain its comfortable temperature. But with active solar, you need continuous sunlight to generate electricity. And this can be problematic at night, on overcast days, or even when a passing cloud goes by.
When there is not enough direct sunlight, most PV systems will switch over to using electricity from the grid. But for critical loads, you may need to install on-site batteries if reliable; uninterrupted access to power is essential for your home or business.
How to Determine Which Solar System Is Best for You
Now that you understand the relative disadvantages and advantages of solar energy, which technology is suitable for your situation – passive vs. active?
Based on the article above, it’s a false choice since the two technologies complement (rather than compete with) one another. Both investments can independently deliver measurable utility bill savings and carbon offsets. And when you combine passive and solar together, these benefits only compound.Equally important, joining the two technologies also reduces the upfront cost of both investments:The more PV panels you add, the fewer passive solar improvements you’ll need, The more passive solar you add, the fewer PV panels you’ll need to power your home.