the separation of migrant families crossing the border with mexico. hundreds of children remain separated despite a change in policy. the united nations human rights council has accused venezuela's security forces of killing hundreds of people under the pretext of fighting crime and then faking evidence to make it look like an exchange of fire. the un human rights chief has called for an international inquiry into the alleged abuses and on day 9 of the world cup, brazil narrowly escaped an embarrassing draw and beat costa rica 2—0. nigeria beat iceland 2—0. that makes it more likely that argentina might be able to qualify from group d. switzerland clinched a two—one victory against serbia it's a celebration of culture, innovation and design in the north of england. the great exhibition of the north, which has just got underway, will last for 80 days. thousands of people lined the banks of the river tyne to watch its launch.

our arts editor will gompertz reports. welcome to our future and all she endows. this is our dream, our vision. lemn sissay, reading his latest poem from the gateshead millennium bridge. this is the backbone of britain. and they say it is cold. it is a rallying cry, an invitation, a love letterfrom him to you to come and see the great exhibition of the north. the great exhibition of the north it signifies and shows the change that's happened. people come to manchester as they come to newcastle and say this is not the place i remember 20, 30 years ago. and it is not and it needs to be writ large in the culture and the mindset of britain. there is no single venue for this great exhibition, a £30 million multisite, three—month event, which the organisers say has something for everybody — from street art to street dance. the turner prize shortlisted artist,

michael dean has put on a powerful, politically—charged show, it is a stark reflection on the realities of poverty and homelessness. i don't like to use expensive materials. i use materials out of fear that i will have to go back to living on a council estate and have absolutely no traction and absolutely no means of supporting myself, other than scrabbling for jobs or looking for hand—outs. so you can still make art when you have naught. it is fair to say not everybody is fully aware of this great exhibition. i honestly don't know much about it. does the north need a great exhibition? i don't know, i think the north's great as it is. it's great they are doing it in the northern area. it brings people to newcastle to see how beautiful it actually really is. the discovery museum has welcomed home a local celebrity. robert stephenson‘s famous rocket, made in newcastle in 1829, is now a star attraction and fine example of the sort of pioneering

northern creativity the exhibition wants to showcase, from the past and the present. look at the northern women around you now. shout about them, appreciate them. it's notjust about history, being able to carbon date them. will gompertz, bbc news, newcastle. in a few minutes it'll be time for newswatch. but first, here's click. florida, america's sunshine state — and home to the us‘s first sustainable town.

this is babcock ranch. powered, befittingly, almost entirely by that big burning ball in the sky. it's 33 degrees. that humidity, i believe, about i,000,000%. and i've come to a solar field, so you don't have too 343,000 solar so you don't have to. 343,000 solar panel spent some 440 acres, providing 75 megawatts of electricity. that's enough to power 15,000 homes. one of the big problems with solar energy has been when the clouds, over or especially when it gets dark, the whole thing effectively goes dead. and we haven't really had a way of storing solar energy until very recently. but over there, ten buildings full of batteries. so it's a start. a pretty good one, too.

babcock has the largest combined solar and storage facility in the us. the batteries can store 40 megawatt hour of electricity, which is enough to keep around 2000 average us homes alight forfour hours. of course, lithium batteries are just one way of storing energy to use later. we've seen other methods before. there's electric mountain in wales, which holds water at a top reservoir until power is needed, it then releases it back down to the lake below. switzerland's air cave fills itself with compressed air and then blows it out to turn turbines. now, over in california, kate russell is on track to see a new solution. since the oil crisis of the 1970s, california has invested heavily into wind and solar power, with the latest state legislation calling for 50% renewable energy by 2030 and all new homes must have solar within two years. the state is way ahead

of its target, so much so that they've had to start paying neighbouring states to take some of the energy from them. as we've heard before, the problem is storage. the grid was built to handle fossil fuel generated power and storage solutions like hydroelectric dams are in short supply. batteries, too, are very bad for the environment, turning unused renewable energy into not such a green solution. california—based company aries have come up with one alternative. aries was really an attempt to think of a way to use the inexhaustible, always reliable power of gravity. we know gravity is going to be there for us. we don't have to worry about shortages or any of that. so how do we use gravity to store and then discharge power when we need it? one of the most efficient ways to move mass, which people have

spent billions of dollars to perfect, are railroads. right. 150 years of experience, incredibly efficient, steel wheels on steel rails are one of the most efficient ways to move mass. dubbed the gravity train, energy is used in electricity to push its weight uphill. when you want to take the energy out you let gravity pull the train back down, using the friction braking to slow the train in order to make power. it's the same way hybrid electric cars like the prius work. you see those wind turbines behind me, they're completely still, even though there is clearly plenty of wind right now. it's not because they're broken, it's because there is no more room to store the energy they would create. and that's the problem the gravity train well solve. when you are into access energy production, use it to power the train up a hill, when you want the energy back, centre the train back down again.

this demo train carries almost five tonnes uphill, storing energy as it goes. a full—scale installation will return 80% of the stored energy, which is not quite as efficient as a huge dam, but has a lot less impact. the amount of energy we store is the weight of the train times the height of the hill. simple mathematics. so the more weight and the higher the hill the more energy we can store. we need long, gently sloping plains. we had clients who approached us and said i only have steep, rocky, craggy mountains, so we have developed a new variation on the aries technology at almost vertical. in october, the company breaks ground on the first full—scale aries in the state of nevada. it'll be used to fine tune the inconsistent energy flows that are a natural part of using solar and wind power. minute by minute it will trim the imbalance between load

and generation on the grid, so our trains may need to go uphill for a minute, they need to go downhill forfive minutes, they are constantly acting like a large flywheel that allows the grid to stay at exactly 60 hertz. it's early days yet and the concept has still to be proved in nevada, but it could help solve one of the renewable industries biggest conundrums right now, balancing the ebb and flow of nature made enemy in a more substantial way. after we run 30 or 40 years providing energy storage and helping people we can remove all of our facilities very quickly, 96% of them can be either repurposed or recycled, so only 4% of our facilities could ever go into a landfill. we are trying to reduce that. we can then plant some native vegetation and six months later you would never know our facility was there. that was kate on a roll

in california. back at babcock i'm going for a solar powered speed in an autonomous shuttle, with its chief financial officer. i guess the motivation for having these autonomous vehicles is that you're encouraging families here to not have as many cars. correct. 0ur thought is that over time most families in the us have a two car family. our hope is that we can get from a two car to a one carfamily. where you have a car for the family, perhaps, but if you have it for a commuterfor work you won't need it any more, you can take an autonomous shuttle or an autonomous vehicle to work. over time, which will take a long time, perhaps, there are no cars. i think, realistically, within the next 10—15 years you can see a time when you go from two car to one car. you think the us government at the moment doesn't... i think they get it. i think they're getting it. the government's a little slow to move, typically. in major cities, major metros, where traffic and pollution are an issue, technology can come in and save a lot of that.

i think governments are willing to step up and make sure this comes to fruition. we're seeing that slowly. what we're hearing and reading about it a lot of major urban cores are going to become, there will be restricted access, if you're driving your car and you're trying to get there you can't get there — up to a certain mile, three miles outside of the city core you you can't get in to the city core without being in an autonomous vehicle, for instance. but outside of autonomous vehicles, building a city or a town that is sustainable, you're not going to be able to do this in colder, more crowded parts of the world. i think that's right. we have a unique situation here, we have the benefit of scale. there are not many people who have 1000 acres of land. that is a big chunk of dirt. along with autonomous shuttles, babcock has its own water and waste facilities, and as and as well as reclaiming water, there is a restriction on the amount you are allowed to use. the tin roofs reflect heat, making homes 10% better at keeping

cool, and the ranch‘s on—site gym is environmentally friendly, too, it's powered by the treadmills. 0ne incentive to get off the couch, i suppose. it is a commendable vision to build a town with all these sustainable values, but i can't help thinking can only really do this when you are building a community from scratch. i mean, could you imagine trying to retrofit an existing town with all of these technologies? you basically have to tear up the infrastructure and tear down all the buildings and start from scratch anyway. babcock has been built in the style of older towns, to attract those who aren't necessarily fans of a new build feel. hi. are you expecting me? people like the kinleys. do you mind if ijust step inside your air—conditioning and stay here forever? they've got a robot vacuum cleaner, a coffee making fridge.... it's set up so it won't spill all over the place.

..and an electric car. for richard, a self—confessed geek and a real fan of click, babcock was his calling. just reading tech blogs all the time on the internet and it sounded fascinating to me. i liked the idea that it was environmentally friendly and was looking forward as far as energy solutions. in atlanta, we lived just downwind from one of the biggest coal polluting plants in the country. i thought that cannot be healthy. i think of it as guilt—free living. in the uk when you have a small town with a central area and you can walk to, it encourages walking, so it's the lifestyle. and while the buildings may look like historic florida, for me it was also all the technology, you know, having 1 gigabyte of fibre optic, internet in the homes...

yeah, you definitely like that. thank you for watching, and we will see you soon. next week we fly up to boston, home of mit, which always offers up 20 very, very cool innovations. looking forward to that. in the meantime, we live on twitter at @bbcclick. thank you for watching, and we will see you soon. hello, and welcome to newswatch with me, samira ahmed. victory for england in the world cup on monday, but we hear why not all bbc news viewers were celebrating. and newsnight‘s emily maitlis has a run—in with a german politician. the first full week of the world cup divided the nation into happy and often excited fans,

and disgruntled, often