Ukraine faces a winter humanitarian crisis unless it can prevent a collapse in its electricity supply caused by the relentless campaign of Russian bombing, the chief executive of the country’s national grid has said. Volodymyr Kudrytskyi, the chief executive of Ukrenergo, said “virtually all” large non-nuclear power stations in the country had been hit, as well as more than 30% of the network’s routing substations. Describing the position as critical, the energy boss said Ukraine had asked western countries for badly needed spare parts last week – and repeated calls for more missile defence systems to help prevent damaging attacks. “This is the biggest missile attack on electricity infrastructure in history. Therefore, the impact is huge. Unfortunately the situation is critical. They are trying to specifically destroy the Ukrainian power system, and this supplies tens of millions of the population,” he said. If the Russian attacks continued, “power cuts in Ukraine will become longer and longer”, Kudrytskyi warned, adding that despite Ukrenergo’s efforts, it was not possible to repair the grid as fast as it was being destroyed. “It’s much easier obviously to launch missiles than to restore substations,” he said. The focus now is on keeping the lights on. “Before these missile attacks, the main goal was to supply as much energy as our customers need. However, now we’re speaking about the survival of the system,” Kudrytskyi told the Guardian during an air raid warning in Kyiv. Electricity was also necessary to sustain gas supplies, the chief executive said. “If the customers will spend too much time without electricity, and if heating systems have no connection to electricity, that will create big, social humanitarian problems.” He said Russia wanted to create “a humanitarian catastrophe” in Ukraine. Power cuts lasting several hours have become increasingly frequent in most areas of the country after a sustained Russian bombing campaign aimed at the electricity network that began last month. For now Ukrainians appear to be coping with the additional uncertainty and hardship without much complaint, accepting it as an unavoidable challenge they must overcome. Under the heading “No Power?”, a co-working space in Kyiv, Kooperativ Kyiv, has advertised that it has two electricity supplies and two internet suppliers so that people can work uninterrupted by the outages. “We’ll get through these times together,” read the advert. Ihor Sudakov, who lives next to a power station in east Kyiv that has been repeatedly hit, said he had attempted to prepare for further outages. “We’ve bought power banks – we keep at least three charged at a time,” he said. “We’ve also ordered this type of charging station that can charge a fridge and stove. Our building only has electricity so if the electricity goes we need to be able to cook.” As a double backup, he said, he had bought a propane camping stove. “I’m not worried that Russia will try to hit the [Kyjv] power station again – I know they will. It’s part of their terrorist tactics … so it’s about trying to be as autonomous as possible.” An attack involving 55 cruise missiles and five drones took place on Monday, aimed at the country’s hydro plants for the first time. Russian missiles targeted the electric infrastructure of the hydro plants, Kudrytskyi said, but not the dams themselves, which are considered more resilient. Although 44 of the missiles were said to have been intercepted by Ukraine, the damage caused on Monday was significant, the chief executive said. “It was in line with the scale of the attack, which was very big. This was a massive attack; massive damage [was] inflicted.” On Monday, 350,000 homes lost power in Kyiv and 80% of the water supply was disrupted after the attack, although both had been restored on Tuesday. Another 20,000 remained without supply in the Kyiv region, said the governor, Oleksiy Kuleba. In Kharkiv, where the main power station was damaged on Monday, Kharkiv hospital number 4 has been running on a reduced voltage – 180W instead of 220W – and there were concerns that this may damage the hospital equipment, said Oleksandr Dukhovsky, the head of paediatric surgery at the hospital. He said the hospital had fewer than five days’ worth of diesel to supply its backup generators. “We are not scared but we understand we need to be careful,” said Dukhovsky, adding that hospital staff were not losing faith and were willing to do what was necessary to win against Russia. Ukrainian officials do not release pictures of the damage to power plants and substations because they do not want Russia to precisely see what impact the attacks are having, but some facilities are acknowledged to have been destroyed. In Ukraine’s eastern Donetsk region, which is now less than 50% controlled by Russian forces and their proxies after recent Ukrainian advances, utilities have been intermittent or absent for months. Dmytro Myshenin of the NGO Vostok SOS, based in Kramatorsk, said that supplies had improved in a few towns but were still absent in places deemed too close to fighting, or very damaged. Towns such as Kramatorsk and Sloviansk had had their water and gas supplies reconnected after the frontline was pushed back and people had returned, he said. But in areas closer to the frontline, people have now spent months living in dire conditions without running water and gas and some also without electricity. “There are many people surviving with portable wood-fired stoves and there aren’t enough of them,” said Myshenin. “We need more of everything.” A week ago, Ukraine sent out lists of replacement parts it needed to the US, UK, EU, and other western countries because “we need a lot of this equipment now”, Kudrytskyi said. He added that there was an urgent need for “western defence systems, which have proven to be very efficient against Russian missiles”. But the chief executive rejected claims that Ukraine could have better prepared. “We’re asking for defence systems all the time. I mean, this is not something new,” he said. “It’s not about our military needs. It’s about humanitarian catastrophe that has to be prevented for tens of millions of people in Europe.” Kudrytskyi said it would be possible for Ukraine – which used to be energy self-sufficient before the Russian attacks – to purchase electricity from Europe. But this would only be a partial help because of the damage to the country’s grid, which would make it harder to route electricity across the country, he said. “We can buy some energy from the EU because the Ukrainian power system is connected to the European power grid,” Kudrytskyi said. “However, we might be unable to deliver this important energy to certain regions, if the grid is damaged.” He also warned there was a danger of transmission bottlenecks. Large cities were at particular risk, he said, because of their huge energy demand. Among these, he listed the country’s main urban centres of Kyiv, Kharkiv, Lviv, Odesa, Zaporizhzhia and Dnipro.