Energy  Mix  and  Renewable  Energies  –  New  Zealand    Hydro-­‐electric  power  in  NZ:  Why  and  How    In  2009  70%  of  New  Zealanders  electricity  came  from  renewable  sources.   In   the  past  New  Zealand  has  garnered  up  to  91%  of   its  electricity   from  renewable  sources.  Water  power   (also  known  as  hydro-­‐electric  power)   is   the  main  source  of  renewable   energy   in  New  Zealand,   generating   over   50%  of   the   country’s   electricity.  New  Zealand’s   largest   rivers,   the  Waikato  in  the  North  Island  and  the  Clutha  in  the  South  Island,  flow  though  several  large  dams  and  power  stations,  where  the   fast  moving  water   can   be   converted   quickly   and   easily   into   electricity.  However,   hydroelectricity   is   subject   to   the  weather   and  New  Zealand's  heavy   reliance  on  hydro  has  been  exposed   in  past   ‘dry  winters'  when  hydro   storage   (lake  levels)  has  dropped,  requiring  careful  management.  Also,  while  Hydroelectricity  produces  no  air  pollution  or  greenhouse  gas   emissions   it   has   been   identified   as   generating   other   adverse   environmental   effects.   The   disruption   of   river   and  riverbank  eco-­‐systems  by  the  creation  of  dams  and  reservoirs  poses  a  great  threat  to  both  native  migratory  fish  species  and   riverside   dwellers   such   as   the   highly   endangered  Black   Stilt.  New  Zealand’s  waterways   still   have   the   potential   to  create  environmentally  friendly  renewable  energy  through  hydropower  with  the  establishment  of  smaller  hydro-­‐electric  stations.   Because   small   hydro   energy   schemes   often   do   not   require   dams   or   significant   storage   they   usually   result   in  significantly  less  impact  on  the  environment  than  large  hydro  schemes.  Small  hydro  schemes  are  projects  below,  roughly,  10  MW   (megawatts)   in   capacity.   This   includes  micro-­‐hydro,   which   is   usually   less   than   10kW   and   is   used   on   domestic  applications.   There   is   currently   over   160MW   collectively   of   small   hydro   schemes   (of   a   size   less   than   20MW)   already  installed   in  New  Zealand   (enough   to   provide   electricity   for   over   80,000   houses)   and   the   potential   for   additional   small  hydro  generation  capacity  is  substantial.    What  are  the  biggest  potentials  concerning  renewable  energy  production  in  your  country  and  what  obstacles  hinder  a  higher  degree  of  their  use  now  or  in  the  future?    In  New  Zealand  almost  one   third  of   our   total   energy   consumption   comes   from   renewable   sources.   This   total   includes  electricity,  heating,  and  transport  fuels.  Two  of  the  most  promising  sources  of  renewable  energy  in  New  Zealand  are  wind  energy,   which   has   already   been   substantially   developed   in   New   Zealand,   and   ocean   energy  which   is   still   in   the   early  stages  of  its  development.    Wind:   As   of   February   2010,   New   Zealand   had   an   installed   wind   generation   capacity   of   497   MW.  Wind   power  now  provides  enough  electricity  to  meet  the  needs  of  160,000  New  Zealand  households,  or  approximately  3%  of  the  country's  electricity  demand.  Wind  farms  with  a  further  capacity  of  80  MW  are  under  construction,  with  approval  granted  or  being  sought   for   another  2,875  MW.  Although  wind  will   probably  never  account   for   a   very   significant  part  of  New  Zealand’s  energy  usage  it  is  valuable  in  that  it  provides  greater  diversity  in  the  way  electricity  is  generated  in  New  Zealand  and  thus  wind   farms  make   the  country   less   vulnerable   to  power   shortages.  A   further  advantage   is   that  wind   farms  do  not  emit  greenhouse   gases   and   while   wind   farms   can   stretch   over   substantial   areas   of   land   the   area   around   the   actual   wind  turbines  can  continue  to  be  used  effectively  for  agriculture  and  farming.  Additionally,  in  future,  wind  power  is  expected  to  become   even  more   cost-­‐effective   as   turbine   technology   gets   cheaper.   A   current   issue   concerns   residents   in   affected  areas   expressing   concern   about   the   visual   impact   of   wind   turbines   on   their   rural   landscape   and   many   instances  communities   have   lobbied   against   the   installation   of   wind   turbines   so   to   protect   the   natural   aesthetics   of   rural   New  Zealand.    Ocean:  New  Zealand  has  large  ocean  energy  resources  but  has  yet  to  harness  their  massive  potential.  TVNZ  reported  in  2007   that   over   20  wave  and  tidal   power  projects   are   currently   under   development   and   from   2008   to   2011,   the  government  Energy   Efficiency   and   Conservation   Authority  has   allocated   $2   million   each   year   from   a   Marine   Energy  Deployment  Fund,  set  up  to  encourage  the  utilisation  of  this  resource.  The  greater  Cook  Strait  and  Kaipara  Harbour  offer  the  most  promising  sites   for  using  underwater  turbines.  Two  resource  consents  have  been  granted  for  pilot  projects   in  Cook  Strait  and  in  the  Tory  Channel,  and  consent  is  being  sought  for  a  project  sites  at  the  entrance  to  the  Kaipara.  Other  potential   locations  include  the  Manukau  and  Hokianga  Harbours,  and  French  Pass.  The  harbours  produce  currents  of  up  to  6  knots  with  tidal  flows  up  to  100,000  cubic  meters  a  second.  These  tidal  volumes  are  12  times  greater  than  the  flows  in  the  largest  New  Zealand  rivers  and  thus  provide  an  exciting  prospect  for  a  country  greatly  concerned  with  the  furthering  of  renewable  energy  production.    

 

 RENEWABLE  ENERGY  =  73%  (Graph  wasn’t  attached)          Sam  Lusk