Here are the 20 tips of ENEA, the National Agency for New Technologies, Energy and Sustainable Economic Development, to save water and energy
First rule: do not waste water. An indication that is always valid, but even more so in a period of water emergency like the one we are experiencing, characterized by the worst drought in the last 10 years. To combat the waste of water and make its management more sustainable, ENEA has developed a 20-point guide with suggestions and good practices, mistakes to avoid, but also solutions and technologies for saving water (and energy), especially in the residential sector. Keywords: at home, reduce losses and waste and more rational uses; in general, adopt less hydro-demanding processes and systems, purification and reuse, efficiency and digitalization of the aqueduct network, but also good practices in the family and in schools. Water saving in 20 points 1. Keep the water system efficient and check for hidden leaks: it is estimated that with a dripping tap you lose up to 5 liters per day. 2. Close the tap tightly to prevent water from flowing unnecessarily. For example, while we are washing our hands: in a minute we avoid the waste of at least 6 liters of water; if while we brush our teeth we let the water flow we waste up to 30 liters (we consume only 1.5 liters if we do not let it flow); Still, turning off the tap when shaving saves up to 20 liters. 3. Collect unused cold water when waiting to receive hot water; first carry out operations that require cold water (for example to brush teeth) and then those that require hot water (for example to shave). 4. Same advice in the kitchen, for food preparation operations or washing vegetables use basins instead of running water. It is estimated that about 6 liters of water per day per capita are consumed for drinking and cooking and at least 40 liters for washing dishes by hand. However, waste can be up to 12 liters per minute if you do not turn off the tap. 5. Reuse the pasta cooking water or vegetable washing to rinse the dishes before putting them in the dishwasher or to water (when it is not salted). 6. Use dishwashers and washing machines always at full load. It is estimated that up to 15 liters (7 liters in class A + ) are used for a load of dishwashers (class A) without pre-washing machine), while for a load of washing machine (class A) 45 liters are used. Also prefer washing programs at low temperatures (40-60 ° C). In addition, with the installation of solar panels you would avoid electricity consumption to heat the water needed by household appliances. 7. Prefer, when possible, taps with sensors or with aerated breaker that reduce the flow of water and have greater washing efficiency, taking care to keep them in efficiency (for example, using the scraper key). 8. Install double-button flushes to save even 100 liters per day, considering that with each use of models with a single button, up to 16 liters of water are used. 9. Choose the shower instead of the bathtub, this way you save up to 1,200 liters per year. It is estimated that to take a bath in the tub you consume on average between 100 and 160 liters of water while to take a 5-minute shower you consume a maximum of 40 liters, even less if you turn off the tap when soaping. 10. Close the central plant in case of prolonged periods of non-use (for example, when leaving for the holidays). 11. Install rainwater collection systems for non-potable uses (toilet washing, car wash) and for watering (rainwater is less hard and more pleasing to plants), avoiding doing it in the hot hours to reduce evaporation. In Italy, on average, about 800 mm of rain falls per year. This means that on an area of about 80 m2 you can collect the necessary water for a person for a year. 12. Use timed, drip or sub-irrigation systems for irrigation, by virtue of their greater efficiency. 13. Avoid washing your car using drinking water, this way we could save 400-500 liters. 14. Cover the surface of the pools with towels to avoid evaporation. 15. Recover condensate water from air conditioners or dryers, for domestic use, such as for iron. 16. Diversify the use of water according to its quality (drinkable, rainy, gray, black – see fig. 2). 17. Use, where possible, technologies for the reuse of grey water, i.e. water generated by personal hygiene operations. A system dedicated to the recycling of water from showers, sinks and tanks and, in some cases, from the condensation of air conditioners or boilers, guarantees its treatment for subsequent use for "secondary" uses such as flushing the toilet, irrigation of green areas, washing operations. 18. In the garden, around the plants, carry out adequate mulching in order to keep as much water as possible in the ground; also prefer plants that need smaller amounts of water and be careful not to irrigate waterproof areas. 19. Install plant covers on roofs and hanging gardens. These are solutions that allow you to absorb up to 50% of rainwater and slow down the outflow of rain into the city's water system, reducing the possibility of flooding in case of heavy rainfall. Green roofs also promote thermal insulation of the roof, reduce fine dust and promote a more pleasant microclimate, reducing the albedo effect. 20. In surfaces outside buildings, use draining flooring in order to preserve the naturalness and permeability of the site, promote groundwater recharge reduce subsidence and mitigate the effect known as heat island. The data According to ENEA estimates, in homes the energy needed for the production of hot water represents about 25% of the total energy used while the average consumption of water for civil use (residential and tertiary) represents about 20% of total consumption, with a per capita water supply (net of losses) of about 200 liters per inhabitant per day. "One of the most critical issues in our country concerns the lack of infrastructure and the poor efficiency of the aqueduct network", underlines Luigi Petta, Head of the Technologies Laboratory for the efficient use and management of water and wastewater ENEA. Despite the high water supply – guaranteed by 7,594 watercourses, 324 lakes, over 1,000 underground aquifers and 526 dams that collect about 11% of the rains – the Italian network loses on average 41.2% of the water injected, with peaks of 48% in national macro-areas. Even in the most virtuous areas, this percentage never falls below 20%, compared to much lower values in Europe (6.5% in Germany)". According to ENEA estimates, the efficiency and digitalization of the aqueduct network would save up to 25% of energy. It is also crucial to save water in the productive sectors; in particular, in our country, fresh water withdrawals for agricultural uses represent about 50% of total water needs; this means that, to face moments of water scarcity like this with damage to agricultural production, it is essential to make irrigation techniques more efficient using those with greater efficiency (subsurface irrigation, undergrowth irrigation, drip irrigation) and focus on research and technological innovation to promote the reuse of treated wastewater. With this objective, ENEA has developed a technologically advanced prototype[4] able to monitor in real time the quality of purified effluents and establish their optimal destinies, including first of all the irrigation of cultivated fields with benefits in terms of greater water availability, nutrient supply, consequent reduction of chemical fertilizers, improving environmental sustainability, quality and safety of the purification chain. "Water is a precious resource. The problems related to its availability, whether they are related to lower rainfall on a seasonal basis, drought, or excess demand compared to usable water resources, affect many areas of the national and European territory and make it necessary to take actions at local and multisectoral level, to be planned over the long term avoiding the use of emergency intervention logics". emphasizes Petta. "In addition, increasing urbanization and ever higher living standards are additional critical factors that require optimal and careful management of the resource." The energy costs of water Uses of water depending on its types