Encouraging the development of true rooftop solar power
Professor Tran Dinh Long
- Dear Professor, over the past time, some rooftop solar power investors have faced difficulties in "payment" because they have not met the prescribed conditions. There have been many debates about this type of energy, so what is your opinion about rooftop solar power?
- The concept of rooftop solar power can be understood as PV systems being installed on roofs of private or public houses, with an area ranging from 40 - 50m2 to 200 - 300m2. The capacity of rooftop solar power is usually not large, just around the electricity need of a household, about 5 - 15kWh. On every residential roof, photovoltaic panels with such capacity can be installed, which is good, not harmful at all because: not large capacity, not much excess power, causing no harm to distribution lines and grids.
However, when being put into practice, people deliberately build large-scale projects that are no longer residential roof PV systems, and solar power now changes to another type. Please keep in mind that special incentives have been introduced for different types of solar power and there are many incentives for true rooftop solar power because of their advantages: not occupying land, lowering indoor heat (leading to less use of cooling electric equipment), protecting roofs thanks to photovoltaic panels, etc.
Therefore, there must be a more specific definition for each type of rooftop solar power. What is a roof, what is a house, a public house or an installation to be exclusively used for production and business, etc., so that there should be separate preferences and regulations. In addition, it is also necessary to clearly define new types of rooftop solar power (such as high-tech agricultural farms, industrial parks, integration of different types, solar energy absorption products such as tiles, wall tiles, etc.) for a specific classification.
If those can be done, this will resolve the inadequacies in the current rooftop solar power development. In my opinion, if it is true rooftop solar power, it should be encouraged and supported with all incentives for development.
Nuclear power may be a trend of the future
- Recently, some opinions have suggested that Vietnam needs to study and consider nuclear power development because this is an important and clean energy source, especially in the context that coal-fired thermal power is not going to be developed, hydropower becomes exhausted and renewable energy is not stable, etc. What is your view on this issue?
- In my opinion, nuclear power is back in people's interest today because it is considered a clean and relatively safe electricity source, nuclear power technology has been advancing and nuclear accidents are unlikely or very rare to happen. If we strictly follow processes and regulations, doing well in the management and operation, risks can be minimized.
Many countries are now returning to nuclear power development, even during the time when this type of electricity was heavily criticized, many countries quietly developed nuclear power and considered this as an inevitable path.
For Vietnam, the development of nuclear power requires consideration at the top leadership level. Therefore, agencies, which are in charge of planning and advising the Government, need to thoroughly study and seek all-inclusive rationales to advise the Party and State on this issue. We can also openly debate, discuss, even solicit public opinion. Personally, I see the need to develop nuclear power.
Need to harmonize power sources
- Recently, many provinces have proposed developing renewable energy and gas-fired power with capacity far exceeding the planned capacity. Meanwhile, renewable energy sources are also facing difficulties because they depend on weather conditions and are not able to be stored; gas-fired power sources require a gas import. What's your opinion on this issue?
- Firstly, the demand for electricity is limited, so when one power source is generated, another must be curtailed. We have hampered the development of coal-fired power plants, gradually phased out and replaced old, polluting power plants with renewable electricity sources. However, if the entire system capacity is based on renewable electricity, when there is no sunlight at night and no wind, what will be the substitutes? This is what planners need to take into account.
Secondly, the role between hydropower and renewable energy must be harmonized. For example, when the sun is at its maximum, hydropower can be curbed to store water; when there is no sunlight, water can be discharged. That is the co-relationship between hydropower and renewable energy.
In addition, we should develop pumped storage hydropower plants, which both store electricity and generate electricity, and can match well with solar power. When solar power is surplus, it will be used to pump water up, and then will be stored as the potential energy for hydropower. When there is no sunlight, water will be discharged to generate electricity, forming a closed-loop circulation system. This type of energy although has been planned in Vietnam for a long time but now being developed at a limited and slow pace. In the context of abundant renewable energy, it is advisable to strongly develop pumped storage hydropower.
The price of this energy is forcedly higher than conventional hydropower but still lower than thermal power or battery storage. On the other hand, pumped storage hydropower does not require large hydraulic resources, which makes it different from conventional hydropower. Pumped storage hydropower needs two reservoirs with different elevations to pump up or discharge water, and then water is only an intermediate mean. This type of power plant can be built even on the coast.