LED 'light bulbs' are now available for really all lamps, even with pleasantly warm light colors. Also, think about the lights outside - are they LED as well?

We must use all suitable areas for photovoltaics (PV), as the alternatives on open spaces restrict nature and agriculture. One trend is PV on stilts, so that gardening or farming can still take place underneath. However, this requires building materials. Thanks to cheap panels from China, photovoltaics has become astonishingly inexpensive today. Unfortunately, there is hardly any money left for feeding into the electricity grid, currently around 8 pence per kWh. Therefore, PV should always be combined with its own electricity storage system (see below) so that as much electricity as possible is consumed by the owner. This saves around 35 pence per kWh, which we would otherwise have to pay to the electricity provider. In this way, your own PV system, adapted to your own electricity consumption, will pay for itself after just a few years. In the case of schools, the question is who is the sponsor. Banks are happy to grant loans for PV, and it is currently also subsidised. In addition, there are also providers who cover the costs and effectively rent the roof space and offer discounted electricity in return. Such providers then form so-called virtual power plants with other houses and their batteries. Citizens can also provide financing through community energy. An electric charging station for teachers or, in the afternoons, on weekends and during holidays, also for the public, could generate income for the operator. Administrative obstacles are there to be overcome."

First of all: private use of hydropower is possible, but absolutely the exception and must be well considered legally and in its effects on ecosystems. We can also only operate wind power plants with consideration for our neighbors (noise development). Some properties are actually sufficiently exposed to the wind. But many are later disappointed with how little yield they have then. Citizen energy really makes sense - if, for example, residents or also local compenies join together in a cooperative and usually operate larger wind turbines nearby. This promotes the acceptance of wind power in the area and the return does not end up with the large investor, but with the local people.

An electricity storage system primarily helps to maximize the yield of the PV system if the electricity is not fed into the grid for little money, but comes from the battery in the evening and then allows the full electricity price to be saved. Another advantage can be that some batteries function as an off-grid system in the event of a power failure. Even if the students may prefer to cancel classes in this case :-) The already mentioned virtual power plants then access your battery from the outside and make the electricity available in the neighborhood and compensate you for it. This stabilizes power grids and even with little wind and no sun, we can live on renewable energies. Note on lithium: Lithium, like many other raw materials, is often problematic during mining. However, the life cycle assessment must take into account that we can recycle lithium over hundreds of years. In the basement, older lithium batteries from the automotive industry could later be given a second life, or sodium batteries that require more space.

Motion detectors make sense in all rooms including outdoor areas, where we potentially let the light burn for too long, for example in the hallway, basement, garage, etc. Of course, it is important that the light does not stay on for too long.

Standby electricity consumption is often admonished and extrapolated. For example, if a TV consumes 5 watts in standby, that is 120 watt hours (Wh) per day, i.e. about one-eighth of a kilowatt hour, which costs about 35 cents. Schools can easily calculate for themselves what savings potential all their computers, copiers and interactive boards etc. have if they do without standby.

Modern lamps require little electricity, but all in all it is worthwhile not to let them burn unnecessarily, for example when we are not in the room for a long time. Corridors, toilet rooms, basements often have the lights on unnecessarily. In some areas, schools also have the lights on too long or too early.

Apart from the fact that every appliance can have a high power consumption, a refrigerator is not defrosted regularly, the door seal is leaking, the washing machine is run at too high temperatures and spin speeds, etc.., there are still some unnecessary things that consume a lot of electricity: In schools, these can be exaggerated light installations, aquarium pumps, etc.

Thermal insulation is extremely important. Investing here means saving energy and costs. The argument that building will then become too expensive must be clearly put into perspective. One way, of course, is to have to insulate smaller living spaces. The other to become generally more efficient when building. Then ecological building materials will also become affordable. Old houses that can no longer be sensibly insulated are perhaps worth so much more as a new building that financing is not a problem. (Note: the figures are for Germany)

Appliances such as washing machines and dishwashers must state a value for water consumption when buying new. It is therefore worthwhile to compare water and energy consumption equally and also to research corresponding test reports, for example from Öko-Test or Stiftung Warentest. Schools usually also have one or the other water-using device.

We can use rainwater at least for garden irrigation in the case of unproblematic materials of the roof. With significantly more effort also for washing machine and toilet flushing. Even if it takes quite a long time economically before it's worth it, it's a good thing.

Building materials such as concrete, plaster, steel or even aluminum have a high ecological footprint and mean many greenhouse gases. The foamed insulation materials are also in the criticism. In addition, the negative consequences of conventional paints and adhesives are often unknown, which then lead to toxic exhaust gases in waste incineration plants due to ultimately ineffective filters. Natural building materials and colors are significantly more expensive, although the non-natural materials are often extremely expensive when it comes to disposal. So it is the good feeling, the better smell and the healthier building biology that make us do the right thing here.

Solar thermal energy makes it possible to heat water over part of the roof area most of the year and then use it for hot water or even to support heating. It is quite inexpensive in the actual purchase - only pipes have to be laid and the heat for the hot water or heating must be transferred via a heat exchanger. Since solar thermal energy works mainly in sunshine, it is often suggested to install PV modules on the same surface and to electrically heat water over them. The yield in kW is higher with solar thermal energy, but the installation of PV is easier.

Ventilation systems have long been standard for passive and active houses. Not only do they help to ventilate properly - so not too late and not too long - but also to remove a large part of the heat from the warm, 'consumed' air. Rare, on the other hand, is wastewater heat recovery.

With old heaters with small radiators, the heating regularly generates over 60 degrees, so that the hot water with over 60 degrees can also be free of legionella. Modern heat pumps, many district heating networks and also the use of solar thermal energy on less sunny days can lead to temperatures of less than 50 degrees for heating. For the hot water, it must then always be reheated elaborately. On the other hand, if the temperature of the hot water can also be lowered, a lot of energy can be saved. However, this is only possible in compliance with the generally accepted rules of technology, otherwise legionella can occur. A help can be modern methods of ultrafiltration.

Most classrooms are too warm in winter - some walk around in T-shirts instead of wearing thick sweaters or a cardigan. The energy-saving potential is considerable.

Air conditioning systems are also gaining in importance in temperate latitudes. Intelligent construction and ventilation and the use of thermal protection roller blinds can avoid these power guzzlers. In warm regions, a corresponding education of the guests can take place. Often a fan is also useful.

Intelligent ventilation does not mean too late and not too long. It is too late when we get tired when we get tired with stale air, get headaches and the humidity becomes too high. It is too long if the air has already been exchanged and is cool, but we also ventilate the materials (walls, furniture) for even longer. Heat ultimately means that things or air vibrate. If the air is exchanged, but the objects and walls are still vibrating, the fresh air is quickly heated. If the walls also get cold, mold can form on them and we need expensive heating energy to get everything vibrating again. By the way, CO2 measuring devices help to ventilate in good time and not for too long. However, these should not be a useless gadget, but perhaps used for practice one after the other in the rooms and should also be lent out. A nice game is the competition to see how good the sense of the people in the room is to ventilate in time and not too long. Schools in particular have the potential to keep the doors in the entrance area not too wide and not too long.

Saving water in schools refers to everything - the toilet flush with the economy button and even waterless pee basins, to automatic taps that only run for a short time, to energy-saving faucets in sinks and showers (gyms).

Vegan means avoiding fish, meat, milk, cheese and other animal foods. Unthinkable for many people, on the one hand because of the taste, and on the other hand because they consider it unhealthy.

Unlike the vegan diet, a vegetarian diet can also include milk, cheese or eggs. Vegetarian days are healthy, mean less animal husbandry and thus less consumption of land and water. People in the industrialized world consume more than three times more animal products, which according to the EAT-Lancet Commission would be healthy for us and the planet. We don't have to become vegans or vegetarians right away, but maybe just flexitarians.

Food from the region, from the weekly market and from the farm shop have not been transported far (there are of course also exceptions there) and strengthen the local economy. However, there are also inefficient short transport routes when vehicles with little load drive to the points of sale. E-mobility and cargo bikes can help here. Unfortunately, the regional is often also played out against the organic offer: regional, sprayed with pesticides food is not as good as regional organic food, and regional meat is not as good for the environment as the renunciation of meat.

Organic is extremely important for biodiversity. We have the greatest extinction of species since the extinction of the dinosaurs and the consequences are greater than those of climate change. Pesticides and mineral fertilizers endanger our future. In addition, soils from organic farming usually store more carbon and thus help against the climate catastrophe.

Which is better - the organic apple from New Zealand or the sprayed apple from the region? Answer: both wrong. Organic food from the region means less transport and is therefore even better than organic food with wide transport. Organic in the canteen or at the kiosk or at events is of course more expensive - but if it is not exemplified somewhere, what do we expect in the private sector. Sometimes a direct delivery from providers from the region is a way to save costs.

Seasonal organic products in addition to regional organic products also have less energy expenditure for storage. In the respective months, other products are available seasonally, so that we can eat healthy and tasty all year round with little transport and storage effort with regard to a seasonal calendar.

Legumes are not only an alternative source of vegetable proter to animal products, but also extremely important for world nutrition. They bind nitrogen from the air in the soil and can achieve just as high yields in organic farming as in industrial agriculture. So we have to cut down fewer forests. In addition, legumes are healthier than cereals. Harari describes in Sapiens how we could probably get much older if we didn't eat so much cereal products. After all, legumes are important for bees and biodiversity. Lupine, for example, also grows in northern Germany and can be used for meat substitutes, yogurt, coffee substitutes, ice cream or even noodles.

Fortunately, tap water has long been a trend. Schools have drinking water dispensers and students have their drinking bottles with them, and managers also bring their drinking bottles to workshops. Many children are not even used to the unhealthy sugar drinks. Tap water is more strictly controlled than bottled beverages and saves a lot of energy and packaging. Schools can set up water dispensers - if necessary, also work with filters, for example to remove chlorine odors.

Food is wasted from the field to the factories and transport routes to the throw away by us, the restaurants and the supermarkets. This ultimately means that more areas are needed for cultivation and thus forests are cut down and biodiversity is endangered with sprays and fertilizers. We can shop more specifically, throw away goods not only because of the best before date, save food in the household (e.g. freeze bananas or make durable spreads and soups from leftover vegetables yourself), save specifically rescued food (e.g. too small or wrinkled goods) and also donate leftover food in many places, e.g. to the food banks. Canteens and kiosks and also events can query the demand in advance and thus prevent food from being thrown away. A dish can also be deliberately offered the next day, which advertises the utilization of the leftovers from the previous day.

Those who do not have a garage or driveway with their own socket are dependent on charging facilities in public spaces and at the workplace. However, the charging options, which are then initially underutilized, must first be there, before people then switch to e-cars with a time delay. Providing teachers with charging stations at the school would be a big step.

For most people, flying is a great experience like experiencing distant places. Flying short-haul routes should rightly lead to 'flight shame' - some countries are planning to ban domestic flights altogether. The problem with flying is, on the one hand, that we cover a lot of kilometers, even if the energy requirement per kilometer and person is not that high. On the other hand, greenhouse gases are transported directly to the heights where they harm us. So we should only use the plane for rare long-distance trips and then stay longer in the places. Unfortunately, flying is even subsidized and is often cheaper than train or car. Nevertheless, school trips should avoid air travel.

What has recently been a successful model in some countries and cities is still a problem in Germany: giving cyclists priority over car traffic. The willingness to ride a bike, even in bad weather, is higher than ever before. E-cargo bikes make it possible to at least do without a second car. A school can do a lot with a bicycle shelter with charging facilities. If teachers or parents are concerned about the theft of e-bikes, schools can also develop ideas for this.

Older e-bikes in particular have to be charged more often and in many families the bicycles are simply not in order because no one has tools or even a functioning pump. The school could also set up a repair station here or even set up a bicycle club to repair bicycles.

No question - leaving the car behind and taking the bike is a proud feeling and healthy. If you don't want to exhaust yourself (for example on the way to work), you can consider an e-bike. If you have a lot to transport, a cargo bike. Often we can also share a cargo bike with others. And if you shy away from bad weather, you will find great cycling clothing today that completely invalidates the argument. Schools can support their teachers here.

We are used to the fact that everything is packed and we don't care much about the packaging. For some foods, the packaging is more expensive in the production than the content. Paying attention to the packaging sends a signal to manufacturers and retailers. Refills are an option as well. For food, there are so-called unpackaged shops or at least the possibility of using deposit containers (own step) or cotton bags brought along for loose vegetables and fruit. To fill up the pantry or to cater for events, attention should therefore be paid to the packaging. Office supplies can be delivered unpacked in deposit boxes (e.g. from Memo).

Consistently separating waste, including green waste, glass and paper, is not as self-evident as one might assume. Many make little effort here and don't really know what belongs in which bin. The residual waste bin also costs the school authority a lot of money, while the recycling and green waste bins are free of charge. Schools should set up separation containers in the classrooms, but also in the corridors and the schoolyard. Most of the time, the argument is that the cleaners only have a garbage bag available and no time. That can definitely be solved. The second argument is that the students do not separate properly. Here, for example, weekly 'environmental services' can be held responsible for the separation, which will certainly sooner or later lead to insight among everyone.

Non-recycled paper is often cheaper, but means cutting of forests, contamination of water during production and a high energy requirement. Recycled paper for toilet paper, writing paper, packaging, envelopes, wrapping paper, etc. should be a matter of course today. But we have to pay attention to it and choose it. Recycled paper is also snow-white, but it should then not be bleached with chlorine but oxygen.

Saving paper helps to protect forests - recycling paper also ultimately means more demand for fresh pulp from trees. We don't even need to print out a lot of things, but can save them on devices that we already have. Digital forms should become more and more popular for internal processes but also for dialogue with students. On the one hand. On the other hand, studies currently differ as to whether complete digitization of teaching or its materials leads to better performance.

Compost toilets are quite controversial - not only because of the proximity to their own faeces, but also because of hygiene, germs, or drug residues. On the other hand, we can no longer give finite artificial fertilizer to the fields and at best collect a little of the nutrients through the sewage treatment plant in order to lead the rest into the seas at the end or to burn the sewage sludge. Compost toilets with microorganisms can ferment faeces and return the nutrients and organic material in cycles of agriculture and the garden. Public compost toilets and also sustainable festivals follow this approach. In terms of approval in the gray area, really comfortable compost toilets are also possible in houses. Odor formation occurs only through the urine. Therefore, compost toilets separate it from the faeces (hence the name separating toilet). Urine is a great fertilizer - we only have to dilute it and of course only apply it to the plants when they also grow. Otherwise, the nitrates will end up in the groundwater with the rain.

After unpackaged and for drinks after tap water, the best thing we can do is to buy our food in reusable containers. (By the way, there are also reusable shipping boxes for office supplies, as is the case with some regional delivery services). Also ask whether the containers are transported empty throughout Germany, or whether North German beer flows into the empty bottle of Bavarian beer and vice versa. The next question is what it costs in energy to clean the containers. Composite packaging or easy-to-recycle cans are the better alternative in some studies. In such studies, you have to look closely at what is being compared. Ultimately, it is important to close regional cycles. Next question is whether the containers should be made of glass or plastic - glass is recycled more often, plastic is lighter and means less energy during transport. If schools are supplied, it should definitely be checked what can be transported in returnable containers.

Much is actually thrown away, although others could still do something with it. It is more convenient for us not to repair it than to have a stall at the flea market or to have to ship it for little money. But the good feeling of doing the right thing motivates. A school can raise awareness here and make appropriate offers, something together with a club or craft lessons. At a school flea market with repair offers, parents and other stakeholders from the region can of course also be involved.

Garbage collection as an event also for the clubs with subsequent meeting, possibly sponsored by the local economy, helps to get nature clean and to raise awareness. Companies can sponsor or participate as a team.

Insect hotels or just old, higher tree stumps and dead wood on the ground, nesting boxes and, if useful, bat boxes are great ways to maximize biodiversity in your own environment. School classes can also participate here.

In the past, it was considered controversial whether birds should be fed, or whether they forget to find food themselves and instead promote the concentration of many birds in one place diseases. Today it is clear that with our well-kept gardens, leaf vacuum cleaners and perfect combine harvesters, we leave too little for the birds and they have to be fed. Many argue that we should even feed them in the summer.

Do we harm regional organic farmers if crops, such as orchards, grow on public land? No, because hardly anyone will be able to take care of themselves. Rather, the main problem is the use of land. English lawns, ornamental plants, weed killers, etc. damage the soil and biodiversity. Instead, nature-friendly crops are needed. If a school shies away from the maintenance effort, permaculture and the cultivation of perennial plants may make sense. The cooperation with beekeepers and school classes, the possibility of public gardening and sponsorships of e.g. senior citizens who take care of the plants during the holidays are also great measures for a better world. Urban gardening is also popular, when schools have raised beds not only on their roofs.

Rare and exotic (not invasive) species often have less yields than our standard products (e.g. apples), but they are usually particularly tasty, encourage conversations with others and help to increase biodiversity. Farms should choose robust plants that can cope even with extreme weather. Diversity ensures resilience against specific diseases.

The awareness of nature-friendly outdoor lighting has increased significantly, there are already so-called star cities that do not want to "pollute" the view of the night sky with light. The street lamps are about whether they shine into the trees or on the street and with which light color they attract how many insects/moths. But we can also do a lot wrong in our gardens, with too bright light, motion detectors that disturb hedgehogs, or those cheap solar lamps that are already hazardous waste with the purchase and do not let the garden get dark in the first place.

Road salt is convenient and safe, but a considerable burden for pets, the trees and the surface water. Replacing this with split means more effort, but it's worth it.

Sidewalks can be kept mechanically or by flames weed-free or the herb can also grow sometimes. The beds can be kept mechanically herb-free or laid out from the outset in such a way that herb does not matter. Pesticides are one of the main causes of species extinction and water pollution.

This is about living and working in the region, about strengthening the community. The birdhouse from a social workshop or the PV system from the electrician on site (if he has further training). The award criteria of the municipalities must of course be legally secure. If the work is good, a discreet advertising sign can also draw attention to the craft business in return.

When we think of fair trade, we usually think of the label of the same name - which is no longer in disrepute. But there are also other labels - some do more greenwashing, but some try to do it better. Fair is not always the same as organic and organic is not always fair (but some labels combine both). The significance is immense: fair working conditions in the world ensure less migration, more climate protection and a more peaceful world. The background to chocolate and the connection between child slavery (!) and the common products from Nutella to children's chocolate to the Mars bar is extremely remarkable: https://www.aktiv-gegen-kinderarbeit.de/2020/07/fuer-unsere-schokolade-werden-kinder-in-westafrika-entfuehrt/ Schools can therefore be pioneers for a better world in the canteens, kiosks or in school uniforms or hand-sewn football.

At first glance, schools are denied this step - they have to remain politically neutral and can actually only indirectly motivate and tolerate students to participate if they participate in demonstrations and not in class.

Schools can offer sustainability days, flea markets, clothing bazaars, food festivals, repair cafes, etc. for citizens to come together.

Societies must take in refugees - no matter how many there are. A distinction must be made between this and the number of those whom we can also integrate into our society in the long term and, with a view to our economy and retirement provision or demographic change. A municipality should actively lead the way and help refugees, take them in and also invite citizens to help, donate and meet the people. Refugees can then also help to help refugees. Linguistically, English is sometimes the lowest common denominator, which can also be chosen in companies. So far as legal, we should help these people. Schools are usually already doing a lot here - integrating refugee children and offering additional language courses. In detail, there are many other great solutions for group work, sponsorships or even voluntary activities in the afternoon, for example for the integration of the other members of the refugee families.

Social department stores are usually organized as a private sector or as an association. A company can support them with material and financial resources.

Cultural promotion can take place in all facets - from young people who make music to exhibitions to the care of traditional festivals.

Bringing people together in the world is more important than ever in times of globalization. Companies can also get involved here beyond the direct economic interest.

Educational trails, information boards, exhibitions, excursions, etc., if necessary also together with schools and nature conservation organizations.

Many schools organize charity runs, charity campaigns (Advent markets) etc. or/and they have partnerships with schools in developing countries. Donations have a double effect - they help the recipients and they reduce the consumption of the givers.

All major drugstore discounters now have natural cosmetics in all areas - from deodont to lipstick to sunscreen (although sustainable sunscreens are a real challenge, as tests prove again and again). On the one hand, natural cosmetics are usually healthier, and on the other hand, no non-degradable substances enter the environment. In the tourism sector, it is accordingly about the soaps in the toilet facilities and on the rooms including shower gels.

Many devices from vacuum cleaners to cordless screwdrivers to TVs are amazingly inexpensive today. Relying on valuable devices that last a long time, or even buying used devices, helps to save raw materials and energy. This means that the caretaker's office can also buy refurbished.

Unfortunately, many devices can no longer be repaired at all, for example if the control unit breaks down from the washing machine and costs more than a new washing machine. And yet there are workshops that also repair mobile phones, washing machines, lawn mowers, etc. - and even if it is as expensive as a new device, it is the good feeling of having done something for a better world again.

This does not mean the skate track or the artificial turf sports field, but motor sports, skiing on artificially snowed slopes, kiting in bird sanctuaries, sailing boats with biocides on the underwater hull, golfing with high water and pesticide use, quad bike rides in nature, parachuting, etc. Of course, these hobbies are fun, which is why it is rewarded if we actively choose the more environmentally friendly alternatives here and thus achieve a change in thinking among others.