Disadvantages of active solar energy are; high capital cost (including for energy storage systems like batteries), geography-dependence, space-intensiveness, potential inadequacy, production and decommissioning-pollution risk.
This article discusses the disadvantages of active solar energy, as follows;
1). High Capital Cost (as one of the Disadvantages of Active Solar Energy)
CAPEX and OPEX in solar-related discussions refer respectively to Capital Expenditure and Operational Expenditure of solar energy systems and projects.
These are estimates of the amount of financial investment expected to be made at the point of purchase and installation, on one hand; and during the operational lifetime of the solar system or project, on the other hand.
However, the CAPEX or capital cost of active solar energy is not always low or affordable.
For concentrated active solar energy systems with parabolic troughs, the initial cost can exceed $7,000 per kilowatt (kW) installed for the most basic configuration, in the absence of sophisticated components and storage systems like hydro-thermal reservoirs or batteries.
In any comparison of passive vs active solar energy, the issue of capital cost is likely to place active solar behind,.as passive solar systems are building-integrated and depend mainly on the design of buildings, without need for expensive external equipment.
Because active solar systems often comprise of multiple components including pumps, conduits and solar collectors; the cost of manufacturing, purchasing and installing these systems may be a deterrent to potential users.
However, like all solar technologies, this cost is often compensated by the low-maintenance, energy-conserving attributes of active solar systems in their operational lifetime.
2). Geography Dependence
Active solar energy comes from electromagnetic waves projected to the Earth’s surface by the Sun. The effectiveness and efficiency of active solar systems depend on how these waves are collected (in form of thermal or infrared-rays, and visible light) by concentrators and panels that have been placed in their path of travel.
Because the amount of solar radiation in any given location or at any point depends on the geographic conditions of the location or point, there is never a 100% guarantee of fair performance for an active solar system.
Four factors that affect solar energy performance are latitude, climate, orientation and elevation. These factors are mostly linked to geography, save few like orientation that can be altered in any geographic location.
The maximum performance of active solar systems is limited to the maximum intensity of solar radiation which they can capture and utilize.
Another challenge is the dependence of active solar heating systems on solar temperature, as exposure to high solar heat can make it un-recommendable to integrate solar panels with active solar heaters due to risk of their (the solar panels’) damage.
Finding suitable locations, and creating suitable system-designs to maximize active solar productivity is often a challenge.
Active solar systems are only productive when they are exposed to an optimal amount of solar radiation, and this excludes periods after sunset. Although efforts are made to integrate energy storage into active solar systems to address inconsistency of energy supply, these geographic constraints still make them less predictable than fossil fuel generators.
3). Space-Intensiveness (as one of the Disadvantages of Active Solar Energy)
Unlike passive solar that is based on the design of the building itself (without addition of any equipment), active solar depends on a number of components that must be installed wherever it is to be used.
Components of active solar systems include reservoirs for working fluid, conduits to circulate the fluid, pumps, valves and solar collectors.
The amount of space which is taken up by a solar system ranges from a few square meters to several thousand-square meters; depending on the scale of the system, its design, configuration and components.
Active solar systems can occupy space on roofs, walls and building interiors, which is a disadvantage given that such space could be put to other uses.
Some active solar power plants for electricity generation, heating or cogeneration are installed on large, remote sites; which could be used for sustainable farming or other basic infrastructural purposes.
Ultimately, the energy output of active solar systems often makes up for the space-intensiveness of these systems.
4). Potential Inadequacy
Active solar energy is often inadequate to meet the energy needs where it is installed.
Inability of solar to cover the energy demands of a given building or district usually leads to reliance on these unsustainable energy options which it is is supposed to replace.
Reasons why active solar systems may not produce enough electricity or heat include limitations of scale, geography, orientation, and conditions of the surroundings, such as trees and other buildings blocking the path of solar radiation.
The efficiency of solar energy capture-and-conversion is also limited by the current level and pace of technological advancement.
5). Production/Decommissioning Pollution Risks
Although it is entirely clean at the point of collection and use, solar energy affects the environment negatively at some stages in its lifecycle of development, including the inceptive manufacturing and installation stages; and the conclusive decommissioning stage.
Solar manufacturing affects the environment because it often requires the extraction of raw materials, and their processing which may involve fossil fuels, atmospheric emissions, and toxic byproducts.
Extraction of raw materials, their processing, transport and installation can affect the ecosystem in a disruptive manner by raising risks of pollution from toxic byproducts, resource depletion of critical raw materials, and general alteration of the environment.
While solar panels are not necessarily a major component of active solar systems, concentrators and conduits are often metallic, and the processes leading from their extraction and refining to the end-product, can cause significant levels of soil, water and air pollution. This is also the case for some non-metallic components used for insulation among other roles.
Decommissioning may also involve some form of environmental degradation, especially for large-scale solar systems. This can arise from the interaction of heavy equipment (used for demolition and removal of active solar components) and their fossil fuel energy-source, with soil, air, vegetation and water.
Disadvantages of active solar energy are;
1. High Capital Cost
2. Geography Dependence
4. Potential Inadequacy
5. Production/Decommissioning Pollution Risks
1). Steffen, B. (2019). “Estimating the Cost of Capital for Renewable Energy Projects.” SSRN Electronic Journal. Available at: https://doi.org/10.2139/ssrn.3373905. (Accessed 21 April 2023).
2). Tsoutsos, T.; Frantzeskaki, N.; Gekas, V. (2005). “Environmental impacts from the solar energy technologies.” Energy Policy, Volume 33, Issue 3, February 2005, Pages 289-296. Available at: https://doi.org/10.1016/S0301-4215(03)00241-6. (Accessed 21 April 2023).