Is it worth buying a generator for blackout days? – 12/17/2023 – Market

Being without electricity has become the new nightmare for São Paulo residents. The last blackouts in the city, in November, left millions of people in the dark – in some cases, for more than a week – and caused damage to all types of establishments, from businesses to municipal schools.

For the common citizen, the trauma also affected their consumer wish list, and electricity generators became the rage. The device was the third most clicked term in the Home and Construction category on Google Trends, according to research released on the eve of Black Friday, at the end of last month.

Residential generators transform the burning of fuels, generally diesel and gasoline, into electrical energy. They are ideal for blackouts and spaces with a scarce distribution network, such as farms, camps and remote places. Furthermore, they only work when the traditional energy grid is suspended, which prevents unnecessary expenses.

But it is a high investment: the devices range from R$600 to more than R$90,000, depending on the brand, electrical power, fuel, autonomy time, noise emission, engine, among other factors. The price is proportional to the supply capacity – that is, the greater the power, the more expensive it is – and options above R$1,000 are the most common.

“Before making any decision, it is important to weigh the scales. How often will you use the generator? How long and how frequent are blackouts where you live? Do you have any special needs that depend on electricity?”, says Vanderlei Martins, MBA professor at FGV (Fundação Getulio Vargas) and specialist in energy planning.

“We don’t have gales and storms like those seen in November every day. You need to weigh whether the investment is worth the need.”

To give you an idea, the cheapest generator, priced at R$600, has one of the lowest electrical powers available on the market, at 800 W (or 0.8 KVa). Powered by gasoline, it keeps some equipment, such as refrigerators and lamps, functioning for up to three hours, depending on what is connected to it. The tank, for this simpler model, has a capacity of up to five liters. This means that, in addition to the initial cost, you also need to pay for the fuel for the hours that the generator will be running.

Devices that run on gasoline and diesel are the most common. “Even though we are in a time of energy transition, renewable sources are not viable due to price and scale”, says Martins. Even solar energy panels, which supply batteries for moments without sunlight, do not have storage capacity for long hours.

For José Aquiles, electrical engineer and professor at the Polytechnic School of USP (University of São Paulo), renewable sources still face another obstacle: availability. “Solar and wind energy depend on weather conditions, so you have no guarantee that you will have supply when the power goes out,” he says.

Among the available options, gasoline-powered generators are quieter than diesel ones, generally cost less and are less polluting. On the other hand, they have lower powers and need more fuel to generate the same amount of energy – which makes supply more expensive.

Those powered by diesel, although noisier and more polluting, have a longer useful life, cost less in maintenance and yield more. For Carlos Olinto, director of the company Essencial Energia, it is still synonymous with greater safety, as gasoline is more flammable. Due to its advantages, diesel is usually the most suitable for residential condominiums, for example, as well as hospitals, industries and other essential services.

“In the case of condominiums, it becomes a much lower cost for the consumer, as it is shared by all residents and lasts more than twenty years”, says Martins.

If you decide to invest in a residential generator, pay attention to the tips below:

• Hire service providers for installation. Although it is not complicated, it requires knowledge of wiring, and contacting a specialized professional mitigates the risk of accidents.

• Calculate the ideal power to meet your needs. To do this, add up the powers of all the equipment you want to work during a blackout. But be careful: refrigerators, freezers and other appliances with induction electric motors consume four times more energy when connected to the generator. This means that, if your refrigerator uses 100W on the normal network, it will use 400W on the generator.

• Count on a safety margin to avoid overloading the generator. In other words, if the sum of your equipment was 1,400W, bet on a device with a nominal power greater than that.

• Pay attention to noise emissions so as not to disturb your neighbors. According to the Law of Silence, noise must not exceed 55 decibels (dB) in the morning and 50 dB at night. Most generators present this information in the technical details.