“Power-plant” Green­houses Are Com­ing

Trillions - - In This Issue -

A ma­genta green­house at the Univer­sity of Cal­i­for­nia, Santa Cruz, is paving the way to a whole new idea of what green­houses can be.

At first, the green­house con­cept de­vel­oped by Michael Loik, a pro­fes­sor of en­vi­ron­men­tal stud­ies at U of C, Santa Cruz, and his col­leagues ap­pears to be sim­i­lar in many re­spects to con­ven­tional green­houses.

Loik’s green­house is set out in the sun and acts as a hot­house lo­ca­tion for rais­ing plants. The plants grown in re­cent ex­per­i­ments us­ing this green­house were toma­toes and cu­cum­bers. The veg­eta­bles were as healthy and de­li­cious as any other green­house-grown ones.

What makes this green­house con­cept unique, how­ever, is that it is a dual-use green­house de­signed from the start to keep the heat from the sun within the struc­ture, so the plants can grow, while also mak­ing it pos­si­ble to cap­ture and con­vert some of that so­lar en­ergy into elec­tric­ity.

This elec­tric­ity-gen­er­at­ing so­lar green­house uses what is known as Wave­length-se­lec­tive Pho­to­voltaic Sys­tems (WSPVS). These sys­tems, which can be op­ti­mized to re­spond to a spe­cific wave­length of light, are able to gen­er­ate more elec­tri­cal power at a lower cost and with higher ef­fi­ciency than or­di­nary “broad­spec­trum” pho­to­voltaic sys­tems.

This so­lar green­house has trans­par­ent roof pan­els that have been soaked in a bright ma­genta lu­mi­nes­cent dye. That dye ab­sorbs a high per­cent­age of the so­lar en­ergy that hits the roof and then trans­fers en­ergy – via lu­mi­nes­cence – to nar­row pho­to­voltaic strips. These strips then con­vert the re­sult­ing light into elec­tri­cal power that can be passed on and/or stored in bat­tery power banks.

Part of the unique green­house de­sign in­volved with WSPVS is that this spe­cific one at U of C, Santa Cruz, ab­sorbs some of the blue and green wave­lengths of light while nat­u­rally pass­ing the rest through. The light that gets through al­lows the hot­house plants to grow, while the light that is ab­sorbed al­lows the hot­house to ef­fi­ciently pro­duce ad­di­tional so­lar-pow­ered elec­tri­cal out­put.

Loik – along with Cather­ine Wade, a grad­u­ate stu­dent; Car­ley Cor­rado, a post-doc­toral re­searcher; and un­der­grad­u­ates David Shugar and Devin Jok­erst, all of Santa Cruz – con­ducted most of the ex­per­i­ments. Carol Ki­tayama, a se­nior grower at Ki­tayama Broth­ers, also par­tic­i­pated in the re­search ef­forts.

What Loik and the rest did in eval­u­at­ing the dual-use de­sign was to look at how well pho­to­syn­the­sis and fruit pro­duc­tion worked with the dual-use sys­tem and the WSPVS. The plants stud­ied even­tu­ally broad­ened to a to­tal of 20 dif­fer­ent va­ri­eties of toma­toes, cu­cum­bers, lemons, limes, pep­pers, straw­ber­ries and basil. Each of the batches was grown in a dual-use ma­genta green­house ei­ther at the univer­sity fa­cil­ity or in nearby Wat­sonville, Cal­i­for­nia, one of the most im­por­tant grow­ing re­gions in the state.

Orig­i­nally, the re­searchers were not sure what might hap­pen and were ex­pect­ing neg­a­tive re­sults. As Loik said, “I thought the pan­els would grow [plants] more slowly, be­cause it’s darker un­der these pink pan­els. The color of the light makes it like be­ing on the Red Planet.” Yet de­spite those plants be­ing sen­si­tive not just to light in­ten­sity but also to color, the re­searchers dis­cov­ered that “it turns out the plants grow just as well” in this un­usual green­house.

In fact, in 80% of the plants eval­u­ated, there was no neg­a­tive im­pact of putting them in this new grow­ing en­vi­ron­ment. Some 20% grew even bet­ter un­der the light of the ma­genta win­dows.

Loik also dis­cov­ered that the “plants re­quired 5% less wa­ter to grow the same amount as in more con­ven­tional green­houses.”

The abil­ity of the green­house to gen­er­ate its own elec­tric­ity is also im­por­tant, since most com­mer­cial green­houses use elec­tric­ity to main­tain tem­per­a­tures as well as power fans, lights and other elec­tri­cal mon­i­tor­ing sys­tems. With the Wspv-tech­nol­ogy pan­els cost­ing only 65 cents per watt of en­ergy gen­er­ated – this is a big win. As Loik, a spe­cial­ist in cli­mate-change stud­ies, plant phys­i­ol­ogy and sus­tain­able tech­nolo­gies, points out, “This tech­nol­ogy has the po­ten­tial to take green­houses off­line.”

In all cases – es­pe­cially con­sid­er­ing that toma­toes and cu­cum­bers are some of the high­est-vol­ume green­house-pro­duced crops world­wide – the re­sults could mean big wins as a busi­ness op­por­tu­nity too. This comes as very good news for U of C, Santa Cruz, physics pro­fes­sors Glenn Aers and Sue Carter, who in­vented the WSPV tech­nol­ogy and then, in 2012, founded a com­pany called Soli­cul­ture to bring it into broader mar­kets and crop use.

All of this points to the sprout­ing up of more of these dual-use ma­genta green­houses in the fu­ture, per­haps even­tu­ally for use through­out the world.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.