Workers prepare the roof of a house to get installed solar power modules for producing heat on October 15, 2011 in Wessling, Germany. Germany has and is continuing to invest heavily in solar energy, both in the public and private sectors. The German government introduced a feed-in tariff with its Renewable Energy Act in 2000 that guarantees homeowners a minimum rate for selling electricity from renewable energy sources into the nation's electricity grid. (Photo by Alexandra Beier/Getty Images)

A view of the facade of a house in the village of Cherevkovo, Arkhangelsk region, Russia, July 12, 2016. Traditional wooden houses, many featuring exquisite carvings and craftsmanship, are falling into decay across Russia because of neglect, lack of funds and an exodus from the countryside to the cities. Urbanisation and a low birth rate are emptying out the countryside, and residents and authorities are often largely indifferent towards the historical value of their properties. (Photo by Maxim Shemetov/Reuters)

Lady Gaga arrives at Nevermind Nightclub on July 11, 2011 in Sydney, Australia. Lady Gaga fans gathered outside two Sydney nightclubs in hopes to catch a glimpse of the singer after she sent a cryptic tweet suggesting her she'd be stopping by the venues. (Photo by Marianna Massey/Getty Images)

Elderly people attend an aquatic exercise at a private pool in Bangkok, Thailand, April 28, 2016. Many Thai families look after elderly relatives at a cost that countrywide adds up to just under a third of household income. The number of families facing this issue will balloon as the population ages at a rate among the fastest in Southeast Asia. (Photo by Athit Perawongmetha/Reuters)

In this photo taken on Saturday, April 29, 2017, a candle is lit in a roadside shrine as the sun sets across a nearby lake of Pineia in the village of Souli, in the Peloponnese region of southern Greece. Made of iron sheeting, stone, wood, concrete or marble, tens of thousands of such shrines punctuate Greece’s roadside scenery, a common sight in a country that has one of the European Union’s worst road fatality rates. (Photo by Petros Giannakouris/AP Photo)

A cow, which escaped from a truck, attacks a farmer trying to catch it in Liangdun village of Nangang township, Anhui province December 15, 2013. The 700 kilogram (1,543 lb) cow attacked several farmers before being shot dead by policemen, local media reported. (Photo by Reuters/China Daily)

Olaf Niess catches swans on the river Alster near the town hall in Hamburg, Germany, 17 November 2015. The Alster swans are moving to their ice-free winter quarters on the Eppendorf Muehlenteich millpond until spring. (Photo by Bodo Marks/EPA)