Indexed rates are offers calculated based on a simple average of the energy price practiced in the wholesale market, relative to the month in which the household consumption occurred. That is, the electricity rate is calculated monthly based on this monthly reference. At the same time, there are dynamic rates in the market in which the calculation of the energy component is done on an hourly basis, which forces the customer to closely monitor the evolution of prices observed in the Spot markets (OMIE/MIBGAS), to avoid the risk of large price fluctuations throughout the day, which can be caused by variations in renewable production, for example. The Regulatory Entity for Energy Services (ERSE) states that "for the customer to be able to take advantage of this type of contract, it is essential to be well informed about the evolution of prices in the electricity markets, in order to have the capacity to react and change consumption quickly over time". The fall in prices in the wholesale energy markets has made indexed and dynamic rates more attractive and led consumers to opt for these solutions, made available by several companies. In ERSE's first quarter bulletin, the commercial electricity offer for a couple with no children with the lowest monthly bill is from Eni Plenitude (Tarifa Tendência) with a value of 31.34 euros/month, which corresponds to a discount of 17% and a monthly saving of 6.33 euros in relation to the regulated rate. Also for families with higher consumption -- a couple with two and four children -- indexed rates are the cheapest: in both cases, Ibelectra's (Solução Família), with a value of 77.23 euros/month, which corresponds to a discount of 19% and a monthly saving of 18.47 euros in relation to the regulated rate in the first case and a value of 165.59 euros/month, which corresponds to a discount of 20% and a monthly saving of 42.62 euros, in the second. In the first quarter of 2024, the difference between the best offer and the offer of the regulated market -- rates defined annually by ERSE -- corresponds to 6.33 euros/month, 18.47 euros/month and 42.62 euros/month, for consumer types 1, 2 and 3, respectively, based on all commercial offers. As for dynamic rates, ERSE does not have simulations because they vary greatly depending on the hourly consumption profile of each consumer, but the regulator expects to launch an offer comparison tool shortly. Currently, EDP Comercial, Endesa, Iberdrola and Goldenergy offer dynamic rates. Market regime marketers that supply more than 200,000 customers and, provided that their consumption facilities have a smart meter, must also make electricity contracts available at dynamic prices, with hourly variable prices, explains the regulator in response to Lusa. When changing to this type of rate, the consumer should pay attention to the issue of unpredictability -- if the trend in price evolution changes, this has an immediate impact on the bill. Therefore, "contracts at dynamic prices promote greater involvement of consumers in the management of their electricity bill, through a response to price signals, stimulating a better view of electricity consumption and improving the rational use of energy", says ERSE. Consumers have the right to change marketers, with no associated charges or any maximum number of changes established. Changing suppliers also does not imply equipment changes (such as a meter) and the maximum period for the change to take effect is three weeks. Read Also: Euro rises against the dollar with the market waiting for the ECB (Portuguese version)